Preparation, surface functionalization and application of Fe3O4 magnetic nanoparticles

Highly sensitive surface plasmon resonance-based sensor using green synthesized Fe3O4/rGO interface layer utilizing plant leaf extracts for alcohol compound detection

In this study, a fast response, real time, accurate, and non destructive alcohol detection method using surface plasmon resonance (SPR) technique was purposed. The SPR measurement was performed using 5-layers Krestchmann configuration with a layer structure of prism/Au thin film/Fe3O4/rGO nanocomposite/alcohol compounds/air. The Fe3O4/rGO nanocomposite was successfully synthesized using the green route utilizing Moringa oleifera and Amaranthus viridis leaf extract. X-ray diffraction analysis showed the nanocomposite has a face-centered cubic with an inverse spinel structure with a crystallite size of 5.6-5.8 nm. The size of Fe3O4 NPs in the Fe3O4/rGO nanocomposite was variated from 10.6-13.0 nm and showed that there is no impurities in the sample. Fourier transform infra-red analysis also validates the existence of Fe3O4 and rGO indicated by the FeO and CC bond, respectively. The interaction between Fe3O4 and rGO can also be observed through the coordinational bonding FeOC, which is validated by the presence of FeO and CO bonds. The optical properties were studied using ultraviolet-visible spectroscopy, which shows an energy gap of 2.36 eV. Magnetic properties of Fe3O4/rGO nanocomposite show a superparamagnetic characteristic with the saturation magnetization of 40.53 emu/g, magnetic susceptibility of 3.62 × 10-2, and the domain size is 6.22 nm. The SPR angle shifts when applied with Fe3O4/rGO nanocomposite. The addition of alcohol compound further shifted the SPR angle by 0.22°, 0.61°, and 1.19° for methanol, ethanol, and IPA, respectively. This noticeable shift shows a possibility for early detection to differentiate these 3 compounds. The presence of a magnetic field further shifts the SPR angle by 0.08°, 0.08°, and 0.10° for 40, 60, and 80 Oe, which indicates an increase in sensitivity. Therefore, the combination of applied magnetic field and green synthesized Fe3O4/rGO nanocomposite as an eco-friendly interface layer are potential to enhance the sensitivity of SPR to detect the alcohol compounds.

Recent advances on photocatalytic degradation of phthalate ester plasticizers using nanomaterial photocatalysts

Phthalate esters (PAEs) are a class of organic ester compounds containing benzene rings, which have been widely applied as additives in various fields, especially as plasticizers in plastic product to improve the flexibility. Due to the non-covalent bonding, PAEs inevitably leach out from the plastic polymers into environments. PAEs are endocrine disruptors, which possess seriously hazards to organisms, such as reproductive and genetic abnormalities. Now, PAEs pollution has become a serious environmental problem. Moreover, due to its difficulty in natural degradation, it has become a widespread concern to eliminate PAEs pollution with energy-saving technology. Among various degradation technologies for organic pollutant removal, photocatalytic degradation has attracted more attentions due to the merits of low energy consumption, high removal efficiency, abundant photocatalyst and low secondary pollution. In this article, the photocatalytic degradation using nanomaterial photocatalysts towards four kinds of typical PAEs were reviewed, including di(2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP), dimethyl phthalate (DMP), and diethyl phthalate (DEP). To improve the photocatalytic degradation efficiency, various semiconductor photocatalysts have been developed, and the optical and electrochemical properties, and the degradation mechanism and pathway have been also discussed. Finally, the challenges and perspectives of photocatalytic technology on PAEs elimination were presented.

Stable and Controllable Magnetic Functionalization of Polymer Microspheres via Covalent Layer-by-Layer Assembly

Magnetic polymer microspheres have attracted significant attention due to their wide applications in bioanalysis. However, achieving stable and controllable magnetic functionalization remains a critical challenge. Here, covalent layer-by-layer (LBL) self-assembly technique was first applied to the magnetic functionalization of polymer microspheres, preparing P(GMA-co-tBMA)@(Fe3O4@APTES/Fe3O4@GPTMS)n (PG@(FeA/FeG)n) microspheres with controllable magnetic content, suppressed detachment of magnetic particles, and surface functionalization. The alternating loading of Fe3O4@APTES nanoparticles and Fe3O4@GPTMS nanoparticles onto the porous P(GMA-co-tBMA) microsphere templates was achieved through covalent bonds formed between amino groups and epoxy groups. The results indicated that the loading capacity of magnetic particles in a single-layer assembly on the porous microspheres reached its upper limit when the mass ratio ω (MFe3O4@APTES/MP(GMA-co-tBMA)) was 0.05:1, at which point the saturation magnetization value of PG@(FeA/FeG)1 microspheres was 3.00 emu/g. PG@(FeA/FeG)n microspheres were prepared under this condition, and their saturation magnetization value were proportionally with the count of layers, reaching 13.90 emu/g at n = 7. Compared to electrostatic self-assembly, the covalent self-assembly strategy reduced magnetic leakage by approximately 83.4%. PGMA was coated onto magnetic PG@(FeA/FeG)3 microspheres utilizing the amino groups on their surface, and subsequent surface carboxylation was developed. Finally, the carboxylated magnetic microspheres were employed as carriers for chemiluminescence immunoassay to detect creatine kinase-MB (CKMB), a biomarker for acute myocardial infarction (AMI), and exhibited higher chemiluminescence intensity compared to commercially available magnetic beads from JSR Corporation. This method provides a novel approach for achieving stable, controllable, and facile loading of other metals and their compounds, organic compounds, and biomolecules onto polymer substrate.

Chitosan/agarose-encapsulated oleic acid-coated magnetite nanoparticles as a chemotherapeutic-loaded scaffold for drug delivery: Physico-chemical and in vitro biological characteristics

Targeted drug delivery (TDD) offers a promising approach to address the limitations of conventional chemotherapy. This study presents a novel drug delivery system using a chitosan (CS)/agarose (AG) scaffold incorporating oleic acid-coated magnetite nanoparticles (MNPs/OA) for controlled doxorubicin release. Hydrothermally synthesized MNPs were functionalized with oleic acid, a biocompatible surfactant, to improve stability before incorporation into a chitosan-agarose (CS-AG) matrix. The formation of the composite AG-CS-MNPs/OA was characterized and verified using different methods, including Fourier-transform infrared spectroscopy (FT-IR), X-ray Diffraction (XRD), field emission scanning electron microscopy (FE-SEM), thermogravimetric analysis (TGA), and vibrating-sample magnetometer (VSM). Chitosan is a valuable biomaterial due to its pH sensitivity, natural origin, biodegradability, biocompatibility, and bio adhesive properties. In-vitro drug release experiments revealed a pH-dependent behavior, with increased DOX release observed under acidic conditions (pH = 4.5), which are characteristic of tumor sites, compared to a neutral (pH = 7.4). The release dynamics, best captured by the Korsmeyer-Peppas model, indicated a Fickian diffusion mechanism. Cytotoxicity assessments on MCF-7 breast cancer cells showed enhanced drug effectiveness at acidic pH, supporting the concept of targeted delivery. These findings suggest that the chitosan/agarose-magnetite scaffold is a promising candidate for pH-sensitive, controlled drug delivery, potentially enhancing cancer treatment by minimizing adverse effects on healthy tissues.

Mannose-modified multifunctional iron-based nanozyme for hepatocellular carcinoma treatment by remodeling the tumor microenvironment

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related deaths worldwide, with conventional treatments often accompanied by severe side effects. Recently, nanozymes have been extensively employed in cancer therapy due to their enhanced enzymatic activities, stability compared to native enzymes. However, a standalone nanozyme exhibits insufficient targeting capability and fails to specifically localize to the pathological site. In this study, we successfully synthesized a multifunctional iron-based-nanozyme delivery system - Fe3O4-OA-DHCA-PEI-MAN@DSF modified with PEI and MAN by the thermal decomposition method. This mannose-modified nanozyme can specifically target HCC cells via an external magnetic field and mannose-mannose receptor (MRC2) binding. In addition, it exhibits good biocompatibility and pH-dependent drug release characteristics. Within the acidic tumor microenvironment, the iron-based nanozyme initiates intracellular fenton reactions, boosting reactive oxygen species (ROS) production, which ultimately induces apoptosis in HCC cells. Concurrently, the disulfiram small molecule released from the Fe3O4-OA-DHCA-PEI-MAN@DSF nanozyme binds to the FROUNT factor within monocyte-macrophages, thereby inhibiting their response to chemotactic signals emitted by liver cancer cells. This process ultimately suppresses the recruitment of macrophages by HCC cells, reshaping the tumor microenvironment and supporting effective liver cancer treatment. Moreover, this nanozyme system holds potential for MRI-guided targeted chemotherapy combined with chemodynamic therapy, aiming to refine the early diagnosis and precision treatment of hepatic carcinoma, and paving the way for the creation of sophisticated integrated nanoplatforms melding diagnostic and therapeutic functionalities.

Dual modification of oil palm leaves-derived silica for simultaneous magnetic solid phase extraction of organophosphorus and organochlorine pesticides in environmental water

This study developed a novel sorbent, magnetic silica-3-mercaptopropyltrimethoxysilane (MagSil-MPTMS) with enhanced organophosphorus (OPPs) and organochlorine (OCPs) pesticide extraction from water samples. Pesticide residues were extracted via magnetic solid-phase extraction (MSPE) and quantified using gas chromatography-mass spectrometry (GC-MS; HP-5MS column, splitless injection, selected ion monitoring (SIM) mode). The sorbent was synthesised from sustainable oil palm leave (OPL)-sourced silica and exhibited a mesoporous, aggregated, and rough structure with a high surface area and strong magnetism. Its functional groups, associated with magnetite, silica, and MPTMS, contributed significantly to its selectivity for OPPs and OCPs. The study employed Plackett-Burman screening followed by Box-Behnken optimisation, which identified sorbent mass, sample volume, and pH as the most significant factors influencing the extraction process (p-value <0.05). At 77 mg sorbent mass, 24 mL sample volume, and 5.8 sample pH, the MagSil-MPTMS recorded exceptional extraction efficiency for diazinon, chlorpyrifos, p'p-DDE, and dieldrin, documenting recovery rates and limits of detection between 86.22 % and 114.86 % and 0.59 ng mL-1-0.65 ng mL-1, respectively. The data also corresponded to the limits of quantification and relative standard deviations of 1.79 ng mL-1-1.98 ng mL-1 and 2.61 %-10.77 %, respectively. Moreover, the MagSil-MPTMS sorbent produced in the present study outperformed non-functionalised materials, a promising alternative for pesticide extraction from water samples. The findings championed sustainable waste management by valorising OPL as a renewable silica source. Furthermore, its 5.5 score of Analytical GREEnness (AGREE) metric contributed to the eco-friendliness of the developed sorbent.

Magnetic mesoporous silica nanoparticles as advanced polymeric scaffolds for efficient cancer chemotherapy: recent progress and challenges

Magnetic mesoporous silica nanoparticles (MMS NPs) stand out as excellent options for targeted chemotherapy owing to their remarkable features, such as extensive surface area, substantial pore volume, adjustable and uniform pore size, facile scalability, and versatile surface chemistry. This review comprehensively explores the latest developments in MMS NPs, emphasizing their design, functionalization, and application in cancer therapy. Initially, we discuss the critical need for targeted and controlled drug delivery (DD) in oncology, highlighting the role of magnetic and MMs in addressing some challenges. Subsequently, the key features of MMS NPs, such as their high surface area, pore structure, and functionalization strategies, are examined for their impact on their DD performance for efficient cancer chemotherapy. The integration of chemotherapy methods such as photothermal therapy and photodynamic therapy with MMS NPs is also explored, showcasing multifunctional platforms that combine imaging and therapeutic capabilities. Finally, we identify the current challenges and provide future perspectives for the development and clinical translation of MMS NPs, underscoring their potential to reshape CT paradigms.

A biomimetic nano-NET strategy for the treatment of MRSA-related implant-associated infection

Methicillin-resistant Staphylococcus aureus (MRSA) has spread across diverse global environments, and MRSA-related infection is a major threat to public health. Implant-associated infection (IAI) caused by MRSA remains a tough global clinical problem. Conventional antibiotic therapy has limited efficacy in treating MRSA-related IAI, and antibiotic abuse has resulted in the emergence of multidrug-resistant bacteria. Hence, there is a necessity to explore more effective approaches to deal with MRSA-related IAI. Herein, inspired by neutrophil extracellular traps (NETs) released by neutrophils to kill microorganisms, this study proposes a novel biomimetic nano-NET strategy using an epsilon-poly-l-lysine-coated CuO2 nanoplatform, denoted as PCPNAs. The function-adaptive nanoplatform exhibited excellent Fenton-like performance, including robust ROS generation and GSH scavenging ability. PCPNAs showed >90% cell viability in mammalian cells and reduced bacterial burden by 7.65 log10 CFU in vitro. Moreover, the positively charged PCPNAs could easily bind to negatively charged MRSA cells through charge-coupling and simultaneously exerted a trapping effect on MRSA cells. Notably, PCPNAs self-assembled into web-like structures to physically trap and kill biofilm bacteria, achieving 99.58% biofilm eradication. Furthermore, PCPNAs showed satisfactory biocompatibility in vivo and displayed ideal anti-bacterial and anti-inflammatory effects in a mouse model with implant-associated infection. With further development and optimization, the biomimetic nano-NET strategy based on PCPNAs provides a new therapeutic option for the treatment of MRSA-related implant-associated infection.

Covalent Crosslinker-Free Photo-Curing 3D Printing of Liquid Metal Composite Hydrogels Based On SI-photoATRP

Photocurable 3D printing (SLA or DLP) materials have garnered considerable attention due to their remarkable efficiency and precision in manufacturing. However, the presence of covalent crosslinking makes the recycling and reuse of printed materials extremely challenging. Here a novel approach to covalent crosslinker-free photo-curing 3D printing (via DLP) of liquid metal (LM) composite hydrogels is reported, leveraging surface-initiated photoinduced atom radical transfer polymerization (SI-photoATRP). The pre-synthesized PHEA-Br macroinitiators are grafted onto the surfaces of LM nanoparticles (LMNPs) by mechanical sonication, stabilizing the LMNPs within the resin solution while simultaneously generating active sites for SI-photoATRP. During the SI-photoATRP process, polymer chains of sufficient length form hydrogen bonds with multiple LMNPs, effectively transforming the LMNPs into crosslinking points. By integrating the aqueous photoATRP system catalyzed by carbon dots, LM@polymer composite hydrogel with complex structures are successfully established through DLP technology. The versatility of the 3D printed hydrogel is investigated by employing HEA, OEGA480, and AAm as the monomers in resin solution, respectively. Notably, all the LM@polymer composite hydrogels can be degraded in aqueous NaOH solution. Furthermore, LM@polymer-based networks exhibit self-repairing capabilities, serve as underwater adhesives, and conduct electricity. This work offers new insights into designing 3D printing materials and sustainable photocurable technology.

Layer-by-layer coating strategy to functionalize the magnetic nanoparticles for their multi-functionalization

Magnetic nanoparticles (MNPs) hold significant potential for a wide range of applications, however, surface modification or bio-conjugation of MNPs often leads to their aggregation and instability. To address this, we proposed a facile method using a layer-by-layer (LbL) coating technique with polyallylamine hydrochloride (PAH) and poly(styrene sulfonic acid) sodium salt (PSS), so as to maintain the dispersion stability and functionality of MNPs. This method enabled us to develop the powerful MNPs towards to their use in the electrochemical biosensor, by combining both the redox probes (ferrocene (Fc), anthraquinone (AQ), or monocarboxymethylene blue (MB)) and bio-probes (IgG). The redox molecules were effectively anchored to the MNPs under the organic solvents, while such functionalized MNPs surface were subsequently protected by the LbL coating process prior to dispersing in high ionic strength solutions (e.g. Phosphate-buffered saline). And the out-layer of polyelectrolyte shell allowed biomolecules to attach to the MNP surface without chemical cross-linking. Our results demonstrated that the TEM size of MNPs@Fc, MNP@AQ and MNP@MB after LbL coating were characterized as 11.0 ± 2.0 nm, 10.5 ± 2.1 nm and 12.4 ± 2.2 nm and these developed redox MNPs of MNPs@Fc, MNPs@AQ and MNPs@MB were characterized by square wave voltammetry (SWV) with their redox intensity of 0.64 ± 0.10 µA, 23.25 ± 0.73 µA and 0.48 ± 0.13 µA, respectively. In addition, the binding efficiency of adsorption between the MNPs and IgG was up to 78%, evidenced by SDS-PAGE gel analysis. This facile method offered a versatile and effective way to functionalize MNPs, combining redox and biological properties for potential applications in disease diagnosis and point-of-care diagnostics.

Synthesis, and characterization of novel chitosan coated superparamagnetic iron oxide nanoparticles to optimization for adsorption of mercury from industrial effluent wastewater

Superparamagnetic iron oxide nanoparticles (SPIONs) were extensively used as novel adsorbents, if coated with a biopolymer-like low molecular weight chitosan that adsorbed and attracted the hazardous mercury, hence improving their versatility. The synthesis of chitosan-coated SPIONs adsorbent was carried out by the chemical co-precipitation method, and its properties were assessed using several types of analytical techniques including FESEM, SEM with EDX, TEM, AFM, VSM, DLS, XRD, FTIR, and TGA analysis. The process involved the application of chitosan as a coating on the SPIONs, which were subsequently used for the treatment of industrial effluent wastewater. This study aimed to remove mercury from the wastewater, which possessed a concentration of 50 ppm. The DPASV methodology is an excellent method for accurately measuring the concentration of Hg (II) utilizing both qualitative and quantitative methods by the 797 VA Computrace. The study found that Chitosan-coated SPIONs showed a remarkable maximum adsorption capacity of 94.4 % for Hg (II) at a pH of 6, using an adsorbent dosage of 10.0 mg/mL. A thermal adsorption study indicates that the adsorption process is thermodynamically favorable. The isotherm models were found to be a strong fit for this study. The adsorption process was well followed by the pseudo-second-order and external diffusion kinetic models. The findings indicated that the chitosan-coated SPIONs nanoparticles could be a cost-efficient adsorbent for the removal of Hg (II) from industrial effluent wastewater.

Magnetic particles (Fe3O4) magnify ion transfer processes at the electrified liquid-liquid interface. Case study: Levamisole detection

This article describes the effect of non-stabilized magnetic particles Fe3O4 (nanoparticles aggregates) addition to the aqueous phase of the polarized liquid-liquid interface (LLI) on the interfacial ion transfer processes. LLI was formed between 1,2-dichloroethane and water solutions (1,2 DCE)|water. The synthesis of Fe3O4 magnetic particles (MPs) was achieved by the co-precipitation method, after which their appearance, size of aggregates, and zeta potential were assessed. All electrochemical measurements reported in this study were performed using cyclic voltammetry (CV). We evaluated the effect of pH and the presence of different concentrations of magnetic Fe3O4 nanoparticles aggregates always initially added to the aqueous phase on tetramethylammonium cation (TMA+), and 4-octylbenzenesulfonic acid (OBS-) ion transfer. We have found that the addition of Fe3O4 MPs followed by their precipitation and LLI interface modification leads to pH dependent magnification of the recorded ionic currents attributed to the cation and anion transfer from the aqueous to the organic phase and vice versa. As such, we have plotted the calibration curves of TMA+ and OBS- in the concentration range of (10-200 μM) revealing that Fe3O4 MPs have a significant effect on detection sensitivity, which is dependent on the interaction between Fe3O4 MPs and the analyte being studied. Finally, we assessed the electrochemical behavior of levamisole at the 1,2-dichloroethane|water interface in the presence and absence of Fe3O4 MPs.

Ecofriendly Sunlight-Mediated Nontoxic Bimetallic Nanoparticles: Synthesis, Reusable Catalytic Membrane, and Biosensor Applications

Bimetallic nanoparticles (BMNPs) combine the desirable properties of two distinct metals that outperform conventional monometallic nanoparticles (NPs). This work presents a novel ecofriendly silver-copper (Ag-Cu) BMNPs synthesis using sunlight as a green reducing agent, enableing rapid Ag-Cu BMNPs formation at room temperature within 10 min. This method exploiting the facile reduction of Ag⁺ to Ag⁰, which subsequently mediates the reduction of Cu2⁺ to Cu⁰ via water radiolysis-generated species. The Ag-Cu BMNPs were integrated into two reusable catalytic membranes: PTFE@Ag-Cu, formed by immobilizing Ag-Cu BMNPs onto a polytetrafluoroethylene (PTFE) syringe filter, and ACF@Ag-Cu, synthesized via in-situ growth of Ag-Cu BMNPs on activated carbon fiber (ACF) cloth. PTFE@Ag-Cu displays exceptional performance and reusability, converting 2100 mL of 0.15 mM p-nitrophenol to p-aminophenol over 105 cycles at a flow rate of 20 mL min-1. The Ag-Cu BMNPs also exhibit peroxidase-mimic activity, enabling colorimetric H2O2 detection with a range of 0-200 mM and a limit of detection (LOD) of 13.3 µM in solution. Further, the Ag-Cu nanoenzyme demonstrates strong potential for electrochemical glucose detection, achieving an LOD of 0.1 µM and sensitivity of 5221 µA × 10-6 m⁻1 cm⁻2.

Advances in magnetic field approaches for non-invasive targeting neuromodulation

Neuromodulation, the targeted regulation of nerve activity, has emerged as a promising approach for treating various neurological and psychiatric disorders. While deep brain stimulation has shown efficacy, its invasive nature poses substantial risks, including surgical complications and high costs. In contrast, non-invasive neuromodulation techniques, particularly those utilizing magnetic fields (MFs), have gained increasing attention as safer, more accessible alternatives. Magnetothermal stimulation has emerged as an innovative method that enables precise modulation of neuronal ion channels through localized heating induced by interaction of MF with biological tissues. This review discusses the principles of MF-based neuromodulation and highlights the critical role of ion channels in synaptic transmission, and the therapeutic potential of these advanced techniques. Additionally, it highlights key challenges such as spatial targeting precision, safety considerations, and the long-term effects of magnetic exposure on brain function. The findings presente the promise of MF-based neuromodulation as a non-invasive, highly targeted therapeutic strategy for conditions such as epilepsy, movement disorders, and neurodegenerative diseases, with potential applications in chronic pain management and future clinical interventions.

Research progress of nano drug delivery systems in the anti-tumor treatment of traditional Chinese medicine monomers

Tumors pose a serious threat to global public health and are usually treated from two aspects: tumor cells and tumor microenvironment. Compared with traditional chemotherapy drugs, traditional Chinese medicine (TCM) monomers have advantages in tumor treatment, such as multiple targets, multiple levels and synergistic intervention. However, most TCM active ingredients have disadvantages such as poor water solubility and stability, which restrict their clinical application. Nano drug delivery systems have the functions of improving the bioavailability of TCM anti-tumor active ingredients, enhancing tissue targeting, achieving controlled drug release, and inhibiting tumor multidrug resistance. Compared with free monomers, they have higher therapeutic effects and fewer side effects. This article summarizes five commonly used anti-tumor TCM monomer nanocarriers, including lipid nanomaterials, exosomes, polymer micelles, carbon nanotubes, and dendrimers, and explains their anti-tumor mechanisms after combining with TCM, such as inhibiting tumor cell proliferation and metastasis, regulating tumor microenvironment, etc. At the same time, the potential of nano drug delivery systems combined with radiotherapy and immunotherapy is discussed, as well as the current problems of potential toxicity, long-term stability, and complex amplification process, as well as future development directions, aiming to provide a reference for promoting the clinical application of nano drug delivery systems for TCM anti-tumor active ingredients.

Microfluidic Synthesis of Magnetic Nanoparticles for Biomedical Applications

Magnetic nanoparticles have attracted great attention and become promising candidates in the biomedicine field due to their special physicochemical properties. They are generally divided into metallic and non-metallic magnetic nanoparticles, according to their compositions. Both of the two types have shown practical values in biomedicine applications, such as drug delivery, biosensing, bioimaging, and so on. Research efforts are devoted to the improvement of synthesis strategies to achieve magnetic nanoparticles with controllable morphology, diverse composition, active surface, or multiple functions. Taking high repeatability, programmable operation, precise fluid control, and simple device into account, the microfluidics system can expand the production scale and develop magnetic nanoparticles with desired features. This review will first describe different classifications of promising magnetic nanoparticles, followed by the advancements in microfluidic synthesis and the latest biomedical applications of these magnetic nanoparticles. In addition, the challenges and prospects of magnetic nanoparticles in the biomedical field are also discussed.

Manganese Phthalocyanine-Based Magnetic Core-Shell Composites with Peroxidase Mimetic Activity for Colorimetric Detection of Ascorbic Acid and Glutathione

Ascorbic acid (AA) and glutathione (GSH) play a pivotal role in health assessment, drug development, and quality control of nutritional supplements. The development of a new and efficient method for their detection is highly desired. In this work, we fabricated magnetic core-shell nanocomposites (Fe3O4@MnPc-NDs) by a one-pot hydrothermal method with citric acid and manganese tetraamino phthalocyanine (MnTAPc) as precursors. Fe3O4@MnPc-NDs exhibited enhanced peroxidase activity compared to bare Fe3O4 nanoparticles, enabling catalytic oxidation of colorless 3,3',5,5'-tetramethylbenzidine (TMB) to blue ox-TMB in the presence of H2O2. Leveraging the antioxidant properties of AA/GSH to reduce ox-TMB, a colorimetric assay achieved a low detection limit of 0.161 μM for AA and 0.188 μM for GSH with broad linear ranges. Moreover, this method displayed high specificity against 12 interfering substances and excellent recyclability (>90% activity after five cycles). Finally, the Fe3O4@MnPc-NDs could act as an efficient colorimetric sensor for accurately detecting AA in genuine VC tablets and GSH in whitening serums with high accuracy. Therefore, Fe3O4@MnPc-NDs exhibited great potential in bioassay applications, benefiting from their outstanding sensitivity and high recycling rate.

A rapid synthesis of magnetic-core mesoporous silica-shell nanostructures - as potential theranostic agents - by means of microwave irradiation and the atrane method

Nowadays, the interest in the design of particles that combine therapy and diagnosis simultaneously to obtain a theranostic material has increased. One of the most used materials for MRI diagnosis is iron oxide, where clusters of superparamagnetic iron oxide (SPIONs) are noteworthy candidates. These particles are of high interest due to their broad range of applications, such as contrast agents, use in magnetic separation processes, and in hyperthermia therapy, among others. One of the major problems with their use is maintaining superparamagnetism while having the highest magnetization-to-particle ratio. In this work, microwave-assisted synthesis of clusters formed by SPIONs has been investigated. This synthesis strategy allows for significant reduction in the time and energy required to obtain SPION clusters. Also, the magnetization-to-particle ratio has been increased in comparison with single SPIONs. Subsequently, the clusters are coated with amorphous silica using the Stöber method, followed by mesoporous (MS) silica using the atrane method, which offers high and conformal coating homogeneity over the clusters. Surfactant extraction was done using a simple mixture of water, ethanol, and sodium chloride - avoiding the use of other organic solvents. Finally, as a proof of concept, the loading and release of a model molecule were studied to confirm that the SPION-NCs@MS presented in this work have great potential as theranostic agents.

Dual Responsive Magnetic DCR3 Nanoparticles: A New Strategy for Efficiently Targeting Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a major cause of cancer deaths globally. Unlike traditional molecularly targeted drugs, magnetically controlled drug delivery to micro/nanorobots enhances precision in targeting tumors, improving drug efficiency and minimizing side effects. This study develops a dual-responsive, magnetically controlled drug delivery system using PEGylated paramagnetic nanoparticles conjugated with decoy receptor 3 (DCR3) antibodies. The clusters demonstrate capabilities for long-range, magnetically driven control and molecular chemotaxis. Paramagnetic PEGylated particles form vortex- and liquid-like drug moieties within a magnetically controlled system. Vortex-like nanoparticle clusters exhibit high controllability and countercurrent movement, while liquid-nanoparticle robot clusters display greater deformability. Upon loading with DCR3 antibodies, the particles navigate along DCR3-protein gradients in blood and tissue, effectively targeting liver tumor sites in vivo. Clusters of DCR3-coupled magnetic nanoparticles target cells that highly express DCR3, thereby effectively inhibiting tumor cell proliferation and migration. Compared with conventional nanomedicine, DCR3-coupled magnetic nanoparticle clusters are capable of delivering controlled drugs over long distances and responding in a molecular-targeting manner. This research is expected to significantly impact the field of precise tumor drug delivery.

Immobilization of Phospholipase D on Fe3O4@SiO2-Graphene Oxide Nanocomposites: A Strategy to Improve Catalytic Stability and Reusability in the Efficient Production of Phosphatidylserine

Phospholipase D (PLD) plays a pivotal role in the biosynthesis of phosphatidylserine (PS), but its practical application is constrained by limitations in stability and reusability. In this study, we successfully fabricated the Fe3O4@SiO2-graphene oxide (GO) nanocomposite by chemical binding of Fe3O4@SiO2 and GO. Subsequently, PLD was immobilized onto the nanocomposite via physical adsorption, with the aim of enhancing catalytic stability, reducing mass transfer resistance, and improving reusability. Under optimal conditions, the immobilization efficiency reached 84.4%, with a PLD loading capacity of 111.4 mg/gsupport. The optimal pH for PS production by immobilized PLD shifted from 6.0 to 6.5, while the optimal temperature increased from 45 °C to 50 °C. Notably, the immobilized PLD demonstrated a shorter reaction time and a higher PS yield, achieving a 95.4% yield within 90 min, compared to the free PLD (78.1% yield within 150 min), representing a 1.04-fold improvement in production efficiency. Furthermore, the immobilized PLD exhibited outstanding storage stability and thermal stability, along with remarkable reusability. Even after being reused for 10 cycles, the PS yield still stays as high as 78.3%. These findings strongly suggest that the Fe3O4@SiO2-GO immobilized PLD has the potential for the efficient production of PS.

Production and Bioseparation Applications of Polyhydroxyalkanoate Nano-Granules Functionalized with Streptavidin

Rapidly growing industrial biotechnology and bio-manufacturing require simple and cost-effective bioseparation tools. A novel strategy of bioseparation based on the streptavidin-decorated polyhydroxyalkanoate (PHA) nano-granules was developed in this study. By fusing to the N-terminus of PHA-associated phasin protein, the streptavidin was one-step immobilized on the surface of PHA nano-granules simultaneously with the accumulation of PHA in recombinant Escherichia coli. About 1.95 g/L of PHA nano-granules (54.51 wt% of cell dry weight) were produced after 48 h bacterial cultivation. The following qualitative and quantitative characterizations demonstrated that the streptavidin accounted for approximately 6.78% of the total weight of the purified PHA nano-granules and confirmed a considerable biotin affinity of 0.1 ng biotin/μg surface protein. As a proof of concept, the nano-granules were further functionalized with biotinylated oligo(dT) for mRNA isolation and about 1.26 μg of mRNA (occupied 2.59%) was purified from 48.45 μg of total RNA, achieving good integrity and high purity with few DNA and rRNA contaminations. Moreover, the nano-granules retained more than 80% of their initial mRNA recovery efficiency after ten cycles of repeated use. The PHA-SAP nano-granules were also functionalized with biotinylated magnetic beads, allowing magnetic recovery of the PHA nano-granules from cell lysates that still needs optimization. Our study provides a novel and expandable platform of PHA nano-granules that can be further functionalized with various biological groups for bioseparation applications. The functional PHA nano-granules have a great potential to serve as bioseparation resin for large-scale purification processes after suitable optimizations for "bench-to-factory" translation, contributing to scalable and sustainable bioprocessing.

Preparation of light-responsive polyacrylamide/carboxymethyl chitosan composite aerogel and its adsorption performance for Li. Int J Biol Macromol 2025;291:138980. [PMID: 39706450 DOI: 10.1016/j.ijbiomac.2024.138980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

As an essential material for manufacturing lithium batteries, the demand of lithium is increasing, which means novel extracting method from various lithium-containing solutions is necessary. Spiropyran molecules undergo a photoisomerization reaction under light, transitioning from a closed-ring form (colorless) to an open-ring form (colored), generating multiple coordination sites to form coordination bonds with metal ions. In this paper, a polyacrylamide/carboxymethyl chitosan composite aerogel grafted with photoresponsive spiropyragroups (Fe3O4/CNTs@PAM/CS-SP), used for extracting lithium from solutions, was prepared by dual cross-linking and vacuum freeze-drying. Batch adsorption experimental results showed that the incorporation of Fe3O4 nanoparticles further enhances its adsorption capability, as it enables rapid separation of the aerogel from water using an external magnetic field and also improves the adsorption efficiency due to its magnetic properties. The aerogel exhibits good adsorption capacity in the pH range of 9-12 and shows selectivity for Li in simulated brine, achieving a maximum adsorption capacity of 176.5 mg/g at 35 °C and a Li concentration of 1 g/L. The preparation of this aerogel offers a novel and effective approach to creating environmentally friendly adsorbents, providing a new method for extracting lithium from lithium-containing solutions.

Magnetic Polymeric Conduits in Biomedical Applications

Magnetic polymeric conduits are developing as revolutionary materials in regenerative medicine, providing exceptional benefits in directing tissue healing, improving targeted medication administration, and facilitating remote control via external magnetic fields. The present article offers a thorough examination of current progress in the design, construction, and functionalization of these hybrid systems. The integration of magnetic nanoparticles into polymeric matrices confers distinctive features, including regulated alignment, improved cellular motility, and targeted medicinal delivery, while preserving structural integrity. Moreover, the incorporation of multifunctional attributes, such as electrical conductivity for cerebral stimulation and optical characteristics for real-time imaging, expands their range of applications. Essential studies indicate that the dimensions, morphology, surface chemistry, and composition of magnetic nanoparticles significantly affect their biocompatibility, degrading characteristics, and overall efficacy. Notwithstanding considerable advancements, issues concerning long-term biocompatibility, biodegradability, and scalability persist, in addition to the must for uniform regulatory frameworks to facilitate clinical translation. Progress in additive manufacturing and nanotechnology is overcoming these obstacles, facilitating the creation of dynamic and adaptive conduit structures designed for particular biomedical requirements. Magnetic polymeric conduits, by integrating usefulness and safety, are set to transform regenerative therapies, presenting a new avenue for customized medicine and advanced healthcare solutions.

Designing iron oxide & silver nanocomposites with phyto- and fungo chemicals for biomedicine: lessons learned

Multifunctional nanoparticles for biomedical applications are widely researched and constantly developed because they provide wider possibilities for therapy and diagnostics. This work aims to summarise our findings towards the design of multifunctional complex iron oxide and silver nanoparticles (NPs) produced from the plants Zingiber officinale and Hypericum perforatum and mushrooms Amanita muscaria and Sparassis crispa. It was revealed that the antimicrobial and anticancer properties of the NPs were a consequence of the combination of silver and phyto- and fungo-chemicals originating from natural species. Moreover, the photoactive properties of the complex iron oxide and silver nanoparticles promoted photodynamic therapy (λexc = 405 nm) that significantly improved the antibacterial (E. coli, S. aureus, B. pumilus, P. fluorescence) and anticancer (HeLa, U2OS cells) effects. Notably, the gel formulations of the NPs based on hyaluronic and alginic acids had advantages over the aqueous dispersions of the NPs. For instance, being embedded into a hyaluronic acid gel, the NPs were more effective against cancer cells due to the improved uptake of hyaluronic acid by cancer cells. Another advantage of gel formulations of the NPs was connected with their microstructural properties; the nanocomposite gel adjusted its microstructure to the substrate topology, mimicking the substrate scale and pattern. Thus, complex ultrasmall iron oxide and silver nanoparticle NPs synthesized with natural extracts and their gel formulations may find diverse applications in the biomedical field, particularly for local cancer treatment and as post-operative bone or tissue scaffold after cancer or chronic osteomyelitis surgery.

Protein Coronation-Induced Cancer Staging-Dependent Multilevel Cytotoxicity: An All-Humanized Study in Blood Vessel Organoids

The protein corona effect refers to the phenomenon wherein nanomaterials in the bloodstream are coated by serum proteins, yet how protein coronated nanomaterials interact with blood vessels and its toxicity implications remain poorly understood. In this study, we investigated protein corona-related vessel toxicity by using an all-humanized assay integrating blood vessel organoids and patient-derived serum. Initially, we screened various nanomaterials to discern how parameters including size, morphology, hydrophobicity, surface charge, and chirality-dependent protein corona difference influence their uptake by vessel organoids. For nanomaterials showing substantial differences in vessel uptake, their protein corona was analyzed by using label-free mass spectra. Our findings revealed the involvement of cancer staging-related cytoskeleton components in mediating preferential uptake by cells, including endothelial and mural cells. Additionally, a transcriptome study was conducted to elucidate the influence of nanomaterials. We confirmed that protein coronated nanomaterials provoke remodeling at both transcriptional and translational levels, impacting pathways such as PI3K-Akt/Hippo/Wnt, and membraneless organelle integrity, respectively. Our study further demonstrated that the remodeling potential of patient-derived protein coronated nanomaterials can be harnessed to synergize with antiangiogenesis therapeutics to improve the outcomes. We anticipate that this study will provide guidance for the safe use of nanomedicine in the future.

PDDA-Assisted Synthesis of Magnetic Fluorescent Fe3O4@SiO2-CQD Composites

Magnetic fluorescent nanomaterials have broad application prospects as taggants in fields such as anticounterfeiting identification, suspicious object tracking, and potential fingerprint recognition in forensic medicine. It is a common method to synthesize magnetic fluorescent composite nanoparticles by preparing a shell on the surface of magnetic particles to load fluorescent materials. In this work, a magnetic fluorescence nanohybrid was synthesized by in situ encapsulation of carbon quantum dots (CQDs) during the preparation of a SiO2 shell on the surface of Fe3O4 nanoparticles. The traditional Stöber method was employed to synthesize the SiO2 shell. Meanwhile, CQDs were introduced into the hydrolysis process of tetraethyl orthosilicate. To address the issue of charge repulsion between the negatively charged hydrolysis intermediate of tetraethyl orthosilicate and the negatively charged CQDs, poly(diallyldimethylammonium chloride) with positive charge was introduced in the synthesis process. The repulsive charges in the reaction system were balanced by poly(diallyldimethylammonium chloride), allowing for the successful encapsulation of CQDs in the SiO2 shell. The structure, morphology, and magnetic and fluorescence properties of the prepared Fe3O4@SiO2-CQDs were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, a vibrating sample magnetometer, and a fluorescence spectrophotometer. The Fe3O4@SiO2-CQDs exhibited excellent magnetic and fluorescence properties, making them suitable for fluorescence labeling on various substrates and showing great potential in labeling, tracing, and fluorescence sensors.

Advances in engineering nanoparticles for magnetic particle imaging (MPI)

Magnetic particle imaging (MPI) is an emerging imaging modality with exciting biomedical applications, such as cell tracking, blood pool imaging, and image-guided magnetic hyperthermia. MPI is unique in that signal is generated entirely by synthetic nanoparticle tracers, motivating precise engineering of magnetic nanoparticle properties including size, shape, composition, and coating to address the needs of specific applications. However, success in many applications and in clinical transition requires development of high-sensitivity and high-resolution tracers, for which there is considerable room for improvement. This review summarizes recent advancements in MPI tracer synthesis and compares reported tracers in terms of sensitivity and resolution. In making these comparisons, we point out inconsistencies in reporting of MPI tracer properties. To overcome this challenge, we propose a list of properties to standardize characterization and reporting of new MPI tracers and improve communication within the field.

Nanoparticles as Drug Delivery Carrier-synthesis, Functionalization and Application

In recent years, advancements in chemistry have allowed the tailoring of materials at the nanoscopic level as needed. There are mainly four main types of nanomaterials used as drug carriers:metal-based nanomaterials, organic nanomaterials, inorganic nanomaterials, and polymer nanomaterials. The nanomaterials as a drug carrier showed advantages for decreased side effects with a higher therapeutic index. The stability of the drug compounds are increased by encapsulation of the drug within the nano-drug carriers, leading to decreased systemic toxicity. Nano-drug carriers are also used for controlled drug release by tailoring system-made solubility characteristics of nanoparticles by surface coating with surfactants. The review focuses on the different types of nanoparticles used as drug carriers, the nanoparticle synthesis process, techniques of nanoparticle surface coating for drug carrier purposes, applications of nano-drug carriers, and prospects of nanomaterials as drug carriers for biomedical applications.

Aligned Hollow Silicon Nanorods Containing Ionic Liquid Enhanced Solid Polymer Electrolytes with Superior Cycling and Rate Performance

The low lithium-ion conductivity of polyethylene oxide (PEO)-based polymer electrolytes limits their application in solid-state lithium batteries and related fields. Here, ionic liquids (ILs) are injected into hollow silicon nanorods (HSNRs) to prepare a composite solid polymer electrolyte (CSPE) with aligned HSNRs containing ILs (F-ILs@HSNRs). Applying a magnetic field promoted uniform dispersion and orientation of F-ILs@HSNRs in CSPE. The addition of F-ILs@HSNRs reduced PEO crystallinity and formed Li+ transport pathways at the F-ILs@HSNRs/PEO interface. Calculations and multi-physics simulations reveal that ILs within F-ILs@HSNRs contribute most to lithium-ion conduction, followed by the F-ILs@HSNRs/PEO interface. When F-ILs@HSNRs are arranged perpendicular to the electrodes, the CSPE exhibits the shortest Li+ migration pathways, resulting in stable and efficient lithium-ion conduction. The conductivity (2.14 × 10-4 S cm-1) and lithium-ion migration number tLi+ (0.307) are the highest, being 125 times and 184% higher, respectively, than those of PEO-LiTFSI, when compared to CSPEs with randomly arranged or parallel-aligned F-ILs@HSNRs. Furthermore, Li|CSPE|Li batteries and LiFePO4|CSPE|Li batteries display stable cycling for over 2000 h, with coulombic efficiency approaching 100%. Excellent electrochemical reversibility is also confirmed in the rate performance test.

Recycling Fe and improving organic pollutant removal via in situ forming magnetic core-shell Fe3O4@CaFe-LDH in Fe(II)-catalyzed oxidative wastewater treatment

Due to its high efficiency, Fe(II)-based catalytic oxidation has been one of the most popular types of technology for treating growing organic pollutants. A lot of chemical Fe sludge along with various refractory pollutants was concomitantly produced, which may cause secondary environmental problems without proper disposal. We here innovatively proposed an effective method of achieving zero Fe sludge, reusing Fe resources (Fe recovery = 100%) and advancing organics removal (final TOC removal > 70%) simultaneously, based on the in situ formation of magnetic Ca-Fe layered double hydroxide (Fe3O4@CaFe-LDH) nano-material. Cations (Ca2+ and Fe3+) concentration (≥ 30 mmol/L) and their molar ratio (Ca:Fe ≥ 1.75) were crucial to the success of the method. Extrinsic nano Fe3O4 was designed to be involved in the Fe(II)-catalytic wastewater treatment process, and was modified by oxidation intermediates/products (especially those with COO- structure), which promoted the co-precipitation of Ca2+ (originated from Ca(OH)2 added after oxidation process) and by-produced Fe3+ cations on its surface to in situ generate core-shell Fe3O4@CaFe-LDH. The oxidation products were further removed during Fe3O4@CaFe-LDH material formation via intercalation and adsorption. This method was applicable to many kinds of organic wastewater, such as bisphenol A, methyl orange, humics, and biogas slurry. The prepared magnetic and hierarchical CaFe-LDH nanocomposite material showed comparable application performance to the recently reported CaFe-LDHs. This work provides a new strategy for efficiently enhancing the efficiency and economy of Fe(II)-catalyzed oxidative wastewater treatment by producing high value-added LDHs materials.

Enhanced Biodiesel Production with Eversa Transform 2.0 Lipase on Magnetic Nanoparticles

This research investigated the usefulness of magnetic iron oxide nanoparticles (Fe3O4) as a support to immobilize the lipase Eversa Transform 2.0 (ET 2.0) to obtain an active and stable biocatalyst, easily recoverable from the reaction medium for applications in the production of biodiesel. Biodiesel was an alternative fuel composed mainly of fatty acid esters with strong transesterification and esterification capabilities. The study focused on the esterification of oleic acid with ethanol to synthesize ethyl oleate. Magnetic nanoparticles were prepared by coprecipitation, then activated with glutaraldehyde and functionalized with γ-aminopropyltriethoxysilane (APTES). The optimal conditions for immobilizing ET 2.0 were pH 10, 25 mM sodium carbonate buffer, an enzymatic load of 200 U/g, and 1 h of contact time, obtaining 78% yield and enzymatic activity of 205.9 U/g. Postimmobilization evaluation showed that the immobilized enzyme performed better than its free form. Kinetic studies were conducted under these optimized conditions (2-96 h at 150 rpm and 37 °C). The biocatalyst was tested for the synthesis of ethyl oleate using oleic acid as the substrate and ethanol, achieving a conversion of 88.1%. Subsequent recirculation tests maintained approximately 80% conversion until the fourth cycle, confirming the sustainability of ester production. Molecular docking studies revealed that the binding affinity for the enzyme-docked oil composition was estimated at -5.8 kcal/mol, suggesting that the combination of the substrate and lipase was stable and suitable for esterification.

AC Magnetometry Using Nano-ferrofluid Cladded Multimode Interferometric Fiber Optic Sensors for Power Grid Monitoring Applications

The AC magnetic field response of the superparamagnetic nano-ferrofluid is an interplay between the Neel and Brownian relaxation processes and is generally quantified via the susceptibility measurements at high frequencies. The high frequency limit is dictated by these relaxation times which need to be shorter than the time scale of the time varying magnetic field for the nano-ferrofluid to be considered in an equilibrium state at each time instant. Even though the high frequency response of ferrofluid has been extensively investigated for frequencies up to GHz range by non-optical methods, harnessing dynamic response by optical means for AC magnetic field sensing in fiber-optic-based sensors-field remains unexplored. Instead, the incorporation of nano-ferrofluid as sensing materials has been only limited to DC magnetic field sensing, often citing their long response time as a limiting factor to AC field sensing. This work reports the finding of high frequency (up to 15 kHz) AC magnetic field sensing capability of nanomagnetic fluid as the cladding material of a fiber-optic multimode interferometry (MMI) structure optimized for the fourth self-imaging spectral response. The key parameter enabling high frequency response is the short response time (<1 ms) achieved by optimizing both the sensing structure and nano-ferrofluid solution. Focus has been imparted on 60 Hz line-frequency profiles of various current/magnetic fields to test the efficacy of these sensors in metering and monitoring current and current-induced magnetic fields in the electrical power grid systems. The magnetic field sensitivity of 240 mV/Gauss per dBm of transmitted power was achieved for 60 Hz field applied via Helmholtz coil, whereas the 60 Hz AC current sensitivity of 2.83 mV/A was measured due to magnetic field induced by current in a straight conducting wire.

Nanomaterials and methods for cancer therapy: 2D materials, biomolecules, and molecular dynamics simulations

This review explores the potential of biomolecule-based nanomaterials, i.e., protein, peptide, nucleic acid, and polysaccharide-based nanomaterials, in cancer nanomedicine. It highlights the wide range of design possibilities for creating multifunctional nanomedicines using these biomolecule-based nanomaterials. This review also analyzes the primary obstacles in cancer nanomedicine that can be resolved through the usage of nanomaterials based on biomolecules. It also examines the unique in vivo characteristics, programmability, and biological functionalities of these biomolecule-based nanomaterials. This summary outlines the most recent advancements in the development of two-dimensional semiconductor-based nanomaterials for cancer theranostic purposes. It focuses on the latest developments in molecular simulations and modelling to provide a clear understanding of important uses, techniques, and concepts of nanomaterials in drug delivery and synthesis processes. Finally, the review addresses the challenges in molecular simulations, and generating, analyzing, and developing biomolecule-based and two-dimensional semiconductor-based nanomaterials, and highlights the barriers that must be overcome to facilitate their application in clinical settings.

Magnetic nanoparticles for use in bioimaging

Magnetic nanoparticles (MNPs) are well-known contrast agents for use in medical imageology, facilitating disease detection via magnetic resonance imaging (MRI). With the development of nanotechnology, various MNPs have been exploited with strong contrast enhancement effects as well as multiple functions to conquer challenges related to the low detection accuracy and sensitivity. In this review, the typical characteristics and types of MNPs are outlined, and the design and fabrication of MNP-based MRI contrast agents as well as multi-mode imaging agents are also introduced by discussing the representative studies. In the pursuit of performance-enhanced MNPs, novel MNPs are expected to be developed as the next generation of contrast agents for precise bioimaging applications in a broad spectrum of fields.

Recent progress and current status of surface engineered magnetic nanostructures in cancer theranostics

Cancer theranostic is the combination of diagnosis and therapeutic modalities for cancer treatment. It realizes a more flexible, precise and non-invasive treatment of patients. In this aspect, magnetic nanostructures (MNSs) have gained paramount importance and revolutionized the cancer management due to their unique physicochemical properties and inherent magnetic characteristics. MNSs have amazing theranostic ability starting from drug delivery to magnetic hyperthermia and magnetic resonance imaging to multimodal imaging in association with radioisotopes or fluorescent probes. Precise regulation over the synthetic process and their consequent surface functionalization makes them even more fascinating. The ultimate goal is to develop a platform that combines multiple diagnostic and therapeutic functionalities based on MNSs. This perspective has provided an overview of the state-of-art of theranostic applications of MNSs. Special emphasis has been dedicated towards the importance of synthetic approaches of MNSs as well as their subsequent surface engineering and integration with biological/therapeutic molecules that decide the final outcomes of the efficacy of MNSs in theranostic applications. Moreover, the recent advancements, opportunities and allied challenges towards clinical applications of MNSs in cancer management have been demonstrated.

Synergistic applications of quantum dots and magnetic nanomaterials in pathogen detection: a comprehensive review

The rapid and accurate detection of pathogens is crucial for effective disease prevention and management in healthcare, food safety, and environmental monitoring. While conventional pathogen detection methods like culture-based techniques and PCR are sensitive and selective, they are often time-consuming, require skilled operators, and are not suitable for point-of-care or on-site testing. To address these limitations, innovative sensor technologies have emerged that leverage the unique properties of nanomaterials. Quantum dots (QDs) and magnetic nanomaterials are two classes of nanomaterials that have shown particular promise for pathogen sensing. This review comprehensively examines the synergistic applications of QDs and magnetic nanomaterials for detecting bacteria, viruses, phages, and parasites.

Oxidative degradation of anionic dyes in wastewater by magnetic lignin micro-nano spheres catalyzed peroxymonosulfate

Lignin has gained significant attention in wastewater treatment due to its abundant resources and good adsorbability. In this work, magnetic lignin micro-nano spheres (Fe3O4@SiO2-LNS) was prepared using alkali lignin as the raw material, and was used as the adsorbent and catalyst to activate peroxymonosulfate (PMS) to build an inhomogeneous catalytic oxidation system (Fe3O4@SiO2-LNS/PMS). The system was then used to remove the stubborn acid blue 9 (AB9) dye in wastewater, and the effects of pH, catalyst dosage, PMS dosage of the system on the removal percentage of AB9 dye and the corresponding degradation mechanism were explored. The results showed that Fe3O4@SiO2-LNS/PMS system had good removal efficiency for AB9 in wastewater, and AB9 dye was completely oxidized and finally degraded into CO2 and H2O. The maximum removal percentage of AB9 was observed when the pH and temperature of the system were 6.0 and 313 K, and the removal percentage of AB9 achieved 100 % when the optimal dosage of Fe3O4@SiO2-LNS and PMS were 3.44 g/L and 53.15 mM, respectively. In addition, Fe3O4@SiO2-LNS had good stability and reusability. This work provides a promising approach for abatement of dyeing wastewater pollution and a new direction for high-value utilization of alkali lignin.

Magnetic adsorbents for removal of bisphenol A: Design strategies of materials and adsorption mechanisms

Bisphenol A (BPA) is a representative endocrine-disrupting chemical widely utilized in the plastic industry, and its leakage into the environment poses various health risks. There is an urgent need for effective removal technologies, and magnetic adsorption shows promise due to its high efficiency and ease of recovering adsorbents. This review provides a comprehensive and critical summary of recent advances in magnetic adsorbents for the removal of BPA. It covers intrinsic magnetic materials and composite magnetic adsorbents which include magnetic organic adsorbents (covalent organic frameworks, β-cyclodextrin-based adsorbents, and molecularly imprinted polymers), magnetic carbonaceous adsorbents (graphene, activated carbon, biochar, and carbon nanotubes), magnetic inorganic adsorbents and magnetic metal-organic frameworks. After comparing and discussing the different magnetic adsorbents, the adsorption mechanisms are summarized, and the advantages and disadvantages are compared and discussed. Strategies for designing magnetic matrices with appropriate morphology and adsorption materials with optimal porous structures are proposed. The challenges associated with maintaining adsorption performance while integrating a magnetic matrix are also discussed. The research direction for future work is also prospected. This review aims to guide the development of magnetic adsorbents for the removal of BPA and other emerging pollutants.

Magnetic recyclable carboxymethyl cellulose/gelatin/citrate@Fe3O4 photo-nanocomposite beads for ciprofloxacin removal via hybrid adsorption/photocatalysis process under solar light as a renewable energy source

Magnetically separable cross-linked carboxymethyl cellulose/gelatin/citrate-functionalized magnetite nanoparticles (Cit-Fe3O4) photo-nanocomposite beads (mCMC/Ge) were synthesized and applied in synergistic adsorption/photocatalytic degradation of ciprofloxacin (Cipro) pharmaceutical pollutant under sunlight irradiation. Various analytical techniques were employed to characterize their structural, textural, magnetic, thermal, and optical properties. The removal efficiency of mCMC/Ge beads was investigated considering different influencing parameters (pH, beads dosage, contact time, Cipro concentration, and temperature). Experimental data modeling indicated that the adsorption process followed pseudo-second-order kinetics and Langmuir isotherm models, with a maximum Langmuir adsorption capacity (qm) of 50 mg g-1 for mCMC/Ge, twice that of the matrix. Photocatalytic activity results showed prominent enhancement in Cipro removal using 1 g L-1 of mCMC/Ge at pH 7, as compared to Cit-Fe3O4, reaching 96 %, 85 %, and 63 % after 180 min of adsorption and 120 min of irradiation for initial pollutant concentrations of 10, 20, and 60 mg L-1, respectively. Furthermore, mCMC/Ge demonstrated efficient removal even in real water sample. The excellent removal performance of mCMC/Ge highlighted the synergy between polymeric matrix template and encapsulated Cit-Fe3O4 in improving Cipro adsorption and photodegradation. Furthermore, facile recyclability and sustained activity over five cycles identify mCMC/Ge photo-nanocomposite as a promising material for removing organic pollutants from contaminated waters.

Synthesis of a nitrogen-rich dendrimer grafted on magnetic nanoparticles for efficient removal of Pb(ii) and Cd(ii) ions

Rapid industrialization, urbanization, and human activities in catchments have presented a significant global challenge in removing heavy metal contaminants from wastewater. Here, a study was conducted to synthesize a nano-magnetic dendrimer based on a trimesoyl core that can be easily separated from the environment using an external magnet (Fe3O4@NR-TMD-G1, Fe3O4@NR-TMD-G2). The synthesized structure was characterized using various conventional techniques such as Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), powder X-ray diffraction (XRD), energy dispersive X-ray analysis (EDX), thermogravimetric analysis (TGA), vibrating sample magnetometry (VSM), and Brunauer-Emmett-Teller surface area analysis (BET). The prepared adsorbent showed good binding ability and excellent adsorption efficiency toward Pb(ii) and Cd(ii) metal ions from aqueous media (98.5%, 93.6%). The effect of different conditions including pH, adsorbate concentration, adsorbent dosage, isotherm, kinetics, and adsorption mechanism was considered. The highest adsorption efficiency was achieved at 25 °C and pH 4 using 0.08 g of Fe3O4@NR-TMD-G1, within 25 minutes for Pb(ii) and 120 minutes for Cd(ii), respectively. Batch adsorption experiments revealed that Fe3O4@NR-TMD-G1 was more effective in removing Pb(ii) and Cd(ii) compared to Fe3O4@NR-TMD-G2, with maximum capacities of 130.2 mg g-1 and 57 mg g-1, respectively. The adsorption process followed the Langmuir isotherm with a high correlation coefficient (R 2 = 0.9952, 0.9817) and non-linear pseudo-second-order kinetic model. Density functional theory (DFT) analysis indicated that the adsorbent transferred electrons to Pb(ii) and Cd(ii), forming stable chelates on the nanostructure surface. The heavy metal ions could be adsorbed by coordination to the heteroatoms of the nanostructure and also by electrostatic interactions. The recycled hybrid nanomaterial was dried and applied to different adsorption-desorption tests and the desorption efficiency was found to be 98%. So, the newly synthesized dendritic magnetic nanostructure demonstrated significant potential in efficient removal of metal ions from water and wastewater, highlighting its importance in addressing the global challenge of heavy metal contamination.

Recent Advances in the Application of Magnetite (Fe3O4) in Lithium-Ion Batteries: Synthesis, Electrochemical Performance, and Characterization Techniques

With the promotion of portable energy storage devices and the popularization of electric vehicles, lithium-ion battery (LiB) technology plays a crucial role in modern energy storage systems. Over the past decade, the demands for LiBs have centered around high energy density and long cycle life. These parameters are often determined by the characteristics of the active materials in the electrodes. Given its high abundance, environmental friendliness, low cost and high capacity, magnetite (Fe3O4) emerges as a promising anode material. However, the practical application of Fe3O4 faces challenges, such as significant volume expansion during cycling. To overcome these obstacles and facilitate the commercialization of Fe3O4, a comprehensive understanding of its properties and behavior is essential. This review provides an overview of recent Fe3O4 research advances, focusing on its synthesis, factors influencing its electrochemical performance, and characterization techniques. By thoroughly understanding the characteristics of Fe3O4 in LiB applications, we can optimize its properties and enhance its performance, thereby paving the way for its widespread use in energy storage applications. Additionally, the review concludes with perspectives on promoting the commercialization of Fe3O4 in LiBs and future research directions.

Magnetic Tunability via Control of Crystallinity and Size in Polycrystalline Iron Oxide Nanoparticles

Iron oxide nanoparticles (IONPs) are widely used for biomedical applications due to their unique magnetic properties and biocompatibility. However, the controlled synthesis of IONPs with tunable particle sizes and crystallite/grain sizes to achieve desired magnetic functionalities across single-domain and multi-domain size ranges remains an important challenge. Here, a facile synthetic method is used to produce iron oxide nanospheres (IONSs) with controllable size and crystallinity for magnetic tunability. First, highly crystalline Fe3O4 IONSs (crystallite sizes above 24 nm) having an average diameter of 50 to 400 nm are synthesized with enhanced ferrimagnetic properties. The magnetic properties of these highly crystalline IONSs are comparable to those of their nanocube counterparts, which typically possess superior magnetic properties. Second, the crystallite size can be widely tuned from 37 to 10 nm while maintaining the overall particle diameter, thereby allowing precise manipulation from the ferrimagnetic to the superparamagnetic state. In addition, demonstrations of reaction scale-up and the proposed growth mechanism of the IONSs are presented. This study highlights the pivotal role of crystal size in controlling the magnetic properties of IONSs and offers a viable means to produce IONSs with magnetic properties desirable for wider applications in sensors, electronics, energy, environmental remediation, and biomedicine.

Magnetic iron oxides nanocomposites: synthetic techniques and environmental applications for wastewater treatment

Nanomaterials are an emerging class of compounds with potential to advance technology for wastewater treatment. There are many toxic substances in industrial wastewater that are dangerous to the aquatic ecosystem and public health. These pollutants require the development of novel techniques to remove them from the environment. Iron oxide nanoparticles are being studied and develop as new technology to address the problem of environmental pollution due to their unique properties and effectiveness against different kind of pollutants. A variety of modified iron oxide nanoparticles have been developed through extensive research that mitigates the shortcomings of aggregation or oxidation and enhances their efficiency as novel remediator against environmental pollutants. In this review, we present synthetic approaches used for the preparation of iron oxide nanoparticles and their corresponding nanocomposites, along with the processes in which the materials are used as adsorbent/photocatalysts for environmental remediation. Applications explored includes adsorption of dyes, photocatalytic degradation of dyes, and adsorption of heavy metal ions. The use of iron oxides nanocomposite in real wastewater samples and recyclability of adsorbents and photocatalysts were also explored.

Nanocomposites of Poly(n-Butyl Acrylate) with Fe3O4: Crosslinking with Hindered Urea Bonds, Reprocessing and Related Functional Properties

In this contribution, we reported the synthesis of the nanocomposites of poly(n-butyl acrylate) with Fe3O4 nanoparticles (NPs) via dynamic crosslinking of poly(n-butyl acrylate)-grafted Fe3O4 NPs with hindered urea bonds (HUBs). Towards this end, the surfaces of Fe3O4 NPs were grafted with poly(n-butyl acrylate-ran-2-(3-tert-butyl-3-ethylureido)ethyl acrylate) chains [denoted as Fe3O4-g-P(BA-r-TBEA)] via living radical polymerization. Thereafter, 1,2-bis(tert-butyl)ethylenediamine was used as a crosslinker to afford the organic-inorganic networks with variable contents of Fe3O4 NPs and crosslinking densities. It was found that the fine dispersion of Fe3O4 NPs in the matrix of poly(n-butyl acrylate) was achieved. The nanocomposites exhibited excellent reprocessing properties, attributed to the introduction of HUBs. Owing to the crosslinking, the nanocomposites displayed excellent shape memory properties. Further, the nanocomposites possessed photo- and magnetic-thermal properties, which were inherited from Fe3O4 NPs. These functional properties allow triggering the shape shifting of the nanocomposites in an uncontacted fashion.

Modern perspectives of heavy metals alleviation from oil contaminated soil: A review

Heavy metal poisoning of soil from oil spills causes serious environmental problems worldwide. Various causes and effects of heavy metal pollution in the soil environment are discussed in this article. In addition, this study explores new approaches to cleaning up soil that has been contaminated with heavy metals as a result of oil spills. Furthermore, it provides a thorough analysis of recent developments in remediation methods, such as novel nano-based approaches, chemical amendments, bioremediation, and phytoremediation. The objective of this review is to provide a comprehensive overview of the removal of heavy metals from oil-contaminated soils. This review emphasizes on the integration of various approaches and the development of hybrid approaches that combine various remediation techniques in a synergistic way to improve sustainability and efficacy. The study places a strong emphasis on each remediation strategy that can be applied in the real-world circumstances while critically evaluating its effectiveness, drawbacks, and environmental repercussions. Additionally, it discusses the processes that reduce heavy metal toxicity and improve soil health, taking into account elements like interactions between plants and microbes, bioavailability, and pollutant uptake pathways. Furthermore, the current study suggests that more research and development is needed in this area, particularly to overcome current barriers, improve our understanding of underlying mechanisms, and investigate cutting-edge ideas that have the potential to completely transform the heavy metal clean up industry.

Application of nanoparticles in breast cancer treatment: a systematic review

It is estimated that cancer is the second leading cause of death worldwide. The primary or secondary cause of cancer-related mortality for women is breast cancer. The main treatment method for different types of cancer is chemotherapy with drugs. Because of less water solubility of chemotherapy drugs or their inability to pass through membranes, their body absorbs them inadequately, which lowers the treatment's effectiveness. Drug specificity and pharmacokinetics can be changed by nanotechnology using nanoparticles. Instead, targeted drug delivery allows medications to be delivered to the targeted sites. In this review, we focused on nanoparticles as carriers in targeted drug delivery, their characteristics, structure, and the previous studies related to breast cancer. It was shown that nanoparticles could reduce the negative effects of chemotherapy drugs while increasing their effectiveness. Lipid-based nanocarriers demonstrated notable results in this instance, and some products that are undergoing various stages of clinical trials are among the examples. Nanoparticles based on metal or polymers demonstrated a comparable level of efficacy. With the number of cancer cases rising globally, many researchers are now looking into novel treatment approaches, particularly the use of nanotechnology and nanoparticles in the treatment of cancer. In order to help clinicians, this article aimed to gather more information about various areas of nanoparticle application in breast cancer therapy, such as modifying their synthesis and physicochemical characterization. It also sought to gain a deeper understanding of the mechanisms underlying the interactions between nanoparticles and biologically normal or infected tissues.

Review on polyaniline-based nanocomposite heterogeneous catalysts for catalytic reduction of hazardous water pollutants

Water contamination by highly toxic substances has generated serious ecological disturbances and health problems for humans. Hence, decontamination of toxic pollutants using advanced, inexpensive, and eco-friendly approaches is the current demand. Heterogeneous catalyst-based catalytic reduction processes have offered the opportunity to transform hazardous water pollutants into non-hazardous products via sustainable, eco-friendly, and efficient routes and might be a competitive substitute for existing traditional water purification techniques. However, the key challenges linked with pure heterogeneous catalysts include agglomeration and poor dispersion, stability, recovery, and reusability, which result in poor activity and efficiency. Thus, it is essential to produce multipurpose polymer-based composite catalysts using conducting polymers, which are exceptionally good supportive and matrix materials. The blending of metal-based nanomaterials with polyaniline conducting polymers produces highly stable and efficient heterogeneous nanocomposite catalysts with amazing catalytic activity against a wide range of water pollutants. The heterogeneous catalytic reductive degradation of immensely toxic pollutant water has gained substantial curiosity because of its excellent physicochemical and surface characteristics, porous structure, recoverability, and recyclability. Therefore, this review presents the latest efforts to generate various polyaniline-based nanocomposite catalysts using a polyaniline matrix and various nanofiller materials and their potential applications in heterogeneous catalytic reduction degradation of water pollutants.

Encapsulating Fe3O4 Nanoparticles and Carbon Dots in a Metal-Organic Framework for Magnetic Fluorescent Taggants

Magnetic fluorescent composite nanomaterials have broad application prospects in the fields of biological imaging, anticounterfeiting identification, suspicious object tracking, and identification of latent fingerprints in forensic medicine. For an effective taggant, a clearly visible identifying mark is necessary to enable observers to capture labeling information quickly and accurately, even from a distance. The preparation method of magnetic fluorescent composite materials is complicated and usually needs different surface modification and assembly processes. The limited loading capacity of fluorescent materials also limits the fluorescence properties of the composite, so it is difficult to produce obvious fluorescence as a taggant to meet the requirements of visible labeling. In this study, a core-shell structure of a magnetic fluorescent composite was prepared by using the metal-organic framework ZIF-8 as the host of fluorescent materials and an encapsulation shell coated on the Fe3O4 nanoparticles. The porous ZIF-8 is beneficial for increasing the loading capacity of fluorescent materials to ensure the fluorescence performance of the composite materials. Further modification of the composite surface prevented the desorption of fluorescent materials from the pores of ZIF-8, enabling the samples to maintain good fluorescence properties even after multiple washing cycles. The preparation method is simple, rapid, and cost-effective, and the prepared magnetic fluorescent composite nanomaterial has high magnetic separation performance and fluorescence performance, making it a promising material for identification, marking, and tracking.

Magnetite-Incorporated 1D Carbon Nanostructure Hybrids for Electromagnetic Interference Shielding

The increasing reliance on electronic technologies has elevated the urgency of effective electromagnetic interference (EMI) shielding materials. This review explores the development and potential of magnetite-incorporated one-dimensional (1D) carbon nanostructure hybrids, focusing on their unique properties and synthesis methods. By combining magnetite's magnetic properties with the electrical conductivity and mechanical strength of carbon nanostructures such as carbon nanotubes (CNTs) and carbon fibers (CFs), these hybrids offer superior EMI shielding performance. Various synthesis techniques, including solvothermal synthesis, in situ growth, and electrostatic self-assembly, are discussed in detail, highlighting their impact on the structure and properties of the resulting composites. This review also addresses the challenges in achieving homogeneous dispersion of nanofillers and the environmental and economic considerations of large-scale production. The hybrid materials' multifunctionality, including enhanced mechanical strength, thermal stability, and environmental resistance, underscores their suitability for advanced applications in aerospace, electronics, and environmental protection. Future research directions focus on optimizing synthesis processes and exploring new hybrid configurations to further improve electromagnetic properties and practical applicability.