Template-Free Synthesis of Porous Fluorescent Carbon Nanomaterials with Gluten for Intracellular Imaging and Drug Delivery

Copper doped carbon dots for selective determination of regulated aniline additives and safe hair dyeing

BACKGROUND

Hair dyes, as common daily chemical products, have been integrated into human daily life. However, the aniline additives contained in traditional hair dyes pose potential threats to health. Therefore, it is of great importance to develop an eco-friendly and convenient detection method and to explore safe alternatives. In this context, enzymatic catalysis technology has received widespread attention due to its safety and eco-friendliness.

RESULTS

Herein, copper-doped carbon dots (CuCDs) with laccase-like activity were prepared by a one-step calcination of copper sulfate, amaranth and ammonium chloride. The resultant CuCDs are monodispersed ellipsoidal crystals with an average diameter of 3.4 nm and active copper centers similar to that of natural laccase. Enzyme kinetics experiments demonstrated that the maximum rate constant (Vmax) obtained from CuCDs is 59 times greater than that of natural laccase, and the Michaelis-Menten constant (Km) is only about half that of natural laccase, indicating a high affinity for laccase substrate. The CuCDs also exhibited a superior stability in comparison with the natural laccase, as over 90 % of their catalytic activity can be maintained in wide pH, temperatures and more than 30 days storage. In the presence of oxygen, CuCDs can not only catalyze the chromogenic reaction of o-phenylenediamine (OPD) and p-phenylenediamine (PPD), allowing for the selective and rapid quantification of these aniline additives in hair dye products, but also catalyze the polymerization of dopamine (DA) under ambient conditions for hair dyeing.

SIGNIFICANCE

This work not only provides an effective method for the determination of aniline additives in hair dyes, but also offers new approaches for safe hair dyeing, and expands the application of carbon nanomaterials in the cosmetics field.

Raspberry-derived carbon dots for specific detection of intracellular copper ions

The detection of intracellular copper ions is crucial for advancing biomedical research and enhancing disease diagnosis. In this study, blue emissive carbon dots (B-CDs) were successfully synthesized using raspberry as the carbon source through a simple hydrothermal method. Characterization techniques combined with theoretical calculations confirmed that the fundamental structural unit of B-CDs is a twelve-membered aromatic ring rich in oxygen and nitrogen functional groups. The B-CDs exhibited high selectivity for Cu2+, showing a strong linear response in the concentration range of 0 to 150 μM, with a detection limit of 0.39 μM. Zeta potential and hydrodynamic size measurements indicated that the B-CDs interact with Cu2+via electrostatic forces. Further studies revealed that the fluorescence quenching of B-CDs in the presence of Cu2+ is primarily due to a dynamic quenching process. Moreover, B-CDs were successfully applied to detect intracellular Cu2+. These findings not only show significant potential of B-CDs in fluorescence sensing but also provide valuable insights for the design of efficient carbon-based sensors.

Nanoparticle-based biomolecules in cancer diagnosis, therapy, drug delivery and prognosis

Introduction

Nanoparticles have orchestrated a paradigm shift in the landscape of cancer diagnosis and therapy, presenting a multifaceted approach to tackle the intricacies of malignancies. This comprehensive exposition delves deep into the forefront of nanomedicine, elucidating pivotal strategies and innovations primed to metamorphose the domain of cancer management.

Methodology

Nanoparticles transcend traditional boundaries, enabling meticulous, site-specific drug release while minimizing systemic toxicity. Intricately designed activation mechanisms, encompassing pH and enzymatic responsivity, along with concentration-dependent strategies, exploit the distinctive attributes of cancer cells, heralding an era characterized by unprecedented therapeutic precision. The pervasive influence of nanotechnology extends to diagnostics, unlocking the realm of early disease detection and personalized treatment. These versatile agents bestow empowering capabilities upon sensitive imaging modalities, affording real-time monitoring and theranostic potential.

Results

This exposition showcases the evolution of cutting-edge nanoplatforms, bridging the chasm between diagnosis and therapy, thereby redefining the confines of cancer care. This review elucidates strategies to combat drug resistance, a perennial challenge within cancer management. By targeting efflux transporters, modulating apoptotic pathways, and countering hypoxia-induced resistance, nanoparticles stand at the vanguard of therapeutic innovation, poised to reinvigorate treatment efficacy.

Discussion & Conclusion

Moreover, this exposé underscores the imminent clinical translation of nanoparticle-based drugs, accentuating their potential to metamorphose the landscape of cancer management. Liposomal vaccines, nano-pharmaceuticals, and nanochemodrugs, currently navigating the crucible of clinical trials, bear immense promise in advancing the realm of precision medicine. In this epoch of precision medicine, nanoparticle-fueled innovations stand poised to propel cancer diagnosis and therapy to unprecedented peaks.

Dual Detection of Norfloxacin and Gatifloxacin by Excitation Tuning Strategy Based on Yellow Carbon Dots

Fluoroquinolones (FQs) are widely used in hospitals, animal husbandry and aquaculture for the treatment of infectious diseases. However, overuse of FQs poses a potential threat to the environment and human. Detection of antibiotics is of great importance in various fields. In this paper, bright yellow fluorescence carbon dots (y-CDs) with quantum yield of 32% were synthesized via a simple and rapid microwave-assisted method using o-phenylenediamine and salicylic acid as raw materials. The fluorescence properties of y-CDs varied under different excitation wavelengths. It is discovered that the excitation wavelength is a critical factor to develop a dual functional fluorescence probe. Under selected excitation wavelength (355 nm), y-CDs can realize dual detection of norfloxacin (NOR) and gatifloxacin (GAT) with good selectivity and high sensitivity in a "turn-on" mode. The detection limits of NOR and GAT are 0.0881 µM and 0.0125 µM, respectively. y-CDs prove practical application in the detection of NOR and GAT in milk and egg samples.

A Review of Conductive Hydrogel-Based Wearable Temperature Sensors

Conductive hydrogel has garnered significant attention as an emergent candidate for diverse wearable sensors, owing to its remarkable and tailorable properties such as flexibility, biocompatibility, and strong electrical conductivity. These attributes make it highly suitable for various wearable sensor applications (e.g., biophysical, bioelectrical, and biochemical sensors) that can monitor human health conditions and provide timely interventions. Among these applications, conductive hydrogel-based wearable temperature sensors are especially important for healthcare and disease surveillance. This review aims to provide a comprehensive overview of conductive hydrogel-based wearable temperature sensors. First, this work summarizes different types of conductive fillers-based hydrogel, highlighting their recent developments and advantages as wearable temperature sensors. Next, this work discusses the sensing characteristics of conductive hydrogel-based wearable temperature sensors, focusing on sensitivity, dynamic stability, stretchability, and signal output. Then, state-of-the-art applications are introduced, ranging from body temperature detection and wound temperature detection to disease monitoring. Finally, this work identifies the remaining challenges and prospects facing this field. By addressing these challenges with potential solutions, this review hopes to shed some light on future research and innovations in this promising field.

Carbon Nanomaterial Fluorescent Probes and Their Biological Applications

Fluorescent carbon nanomaterials have broadly useful chemical and photophysical attributes that are conducive to applications in biology. In this review, we focus on materials whose photophysics allow for the use of these materials in biomedical and environmental applications, with emphasis on imaging, biosensing, and cargo delivery. The review focuses primarily on graphitic carbon nanomaterials including graphene and its derivatives, carbon nanotubes, as well as carbon dots and carbon nanohoops. Recent advances in and future prospects of these fields are discussed at depth, and where appropriate, references to reviews pertaining to older literature are provided.

Carbon dots from alcohol molecules: principles and the reaction mechanism

Carbon dots (CDs) have attracted significant attention in the energy, environment, and biology fields due to their exceptional physicochemical properties. However, owing to the multifarious precursors and complex reaction mechanisms, the production of carbon dots from organic molecules is still a mysterious process. Inspired by the color change of sodium hydroxide ethanol solution after standing for some time, in this work, we thoroughly investigated the reaction mechanism from alcohol molecules to carbon dots through a lot of experiments and theoretical calculations, and it was found that the rate-controlling reaction is the formation of aldehydes, and it is also confirmed that there is a self-catalysis reaction, which can accelerate the conversion from alcohol to aldehyde, further facilitating the final formation of CDs. After the rate-controlling reaction of alcohol to aldehyde, under strongly alkaline conditions, an aldol reaction occurs to form unsaturated aldehydes, followed by further condensation and polymerization reactions to form long carbon chains, which are cross-linked and dehydrated to form carbon dots with a carbon core and surface functional groups. Additionally, it is found that the reaction can be largely accelerated with the assistance of electricity, which indicates the great prospect of industrial production. Furthermore, the obtained CDs with rich functional groups can be utilized as electrolyte additives to optimize the deposition behavior of Na metal, manifesting great potential towards safe and stable Na metal batteries.

Zero-Dimensional Carbon Nanomaterials for Fluorescent Sensing and Imaging

Advances in nanotechnology and nanomaterials have attracted considerable interest and play key roles in scientific innovations in diverse fields. In particular, increased attention has been focused on carbon-based nanomaterials exhibiting diverse extended structures and unique properties. Among these materials, zero-dimensional structures, including fullerenes, carbon nano-onions, carbon nanodiamonds, and carbon dots, possess excellent bioaffinities and superior fluorescence properties that make these structures suitable for application to environmental and biological sensing, imaging, and therapeutics. This review provides a systematic overview of the classification and structural properties, design principles and preparation methods, and optical properties and sensing applications of zero-dimensional carbon nanomaterials. Recent interesting breakthroughs in the sensitive and selective sensing and imaging of heavy metal pollutants, hazardous substances, and bioactive molecules as well as applications in information encryption, super-resolution and photoacoustic imaging, and phototherapy and nanomedicine delivery are the main focus of this review. Finally, future challenges and prospects of these materials are highlighted and envisaged. This review presents a comprehensive basis and directions for designing, developing, and applying fascinating fluorescent sensors fabricated based on zero-dimensional carbon nanomaterials for specific requirements in numerous research fields.

Carbon Nanomaterials (CNMs) in Cancer Therapy: A Database of CNM-Based Nanocarrier Systems

Carbon nanomaterials (CNMs) are an incredibly versatile class of materials that can be used as scaffolds to construct anticancer nanocarrier systems. The ease of chemical functionalisation, biocompatibility, and intrinsic therapeutic capabilities of many of these nanoparticles can be leveraged to design effective anticancer systems. This article is the first comprehensive review of CNM-based nanocarrier systems that incorporate approved chemotherapy drugs, and many different types of CNMs and chemotherapy agents are discussed. Almost 200 examples of these nanocarrier systems have been analysed and compiled into a database. The entries are organised by anticancer drug type, and the composition, drug loading/release metrics, and experimental results from these systems have been compiled. Our analysis reveals graphene, and particularly graphene oxide (GO), as the most frequently employed CNM, with carbon nanotubes and carbon dots following in popularity. Moreover, the database encompasses various chemotherapeutic agents, with antimicrotubule agents being the most common payload due to their compatibility with CNM surfaces. The benefits of the identified systems are discussed, and the factors affecting their efficacy are detailed.

Spleen-Targeted mRNA Delivery by Amphiphilic Carbon Dots for Tumor Immunotherapy

In recent years, the application of mRNA vaccine-based tumor immunotherapy invigorated anti-tumor therapy. However, the low efficiency of mRNA delivery and the lack of targeting ability in vivo are the major obstacles to achieving highly efficient immunotherapy. In this work, we report a chemical library of amphiphilic carbon dots (ACDs) and the synthesized ACDs were applied to mRNA delivery, bio-imaging, and tumor immunotherapy. The ACDs can smoothly bind with mRNA to form ACDs@mRNA nanocomplexes, and the fluorescent properties of the ACDs afforded the nanoparticles with bio-imaging ability. By screening of the ACDs, O₁₂-Tta-CDs were found to have optimal mRNA transfection efficiency and the ability of spleen-targeted delivery. In addition, O₁₂-Tta-CDs can well transfect the immune cells and promote the maturation and antigen presentation of bone marrow-derived dendritic cells (BMDCs). Furthermore, O₁₂-Tta-CDs@OVA-mRNA was successfully applied to inhibit tumor growth, and more specific T-cell infiltration was observed in spleen and tumors of mice after treatment in the E.G7-OVA tumor model. Besides, O₁₂-Tta-CDs@OVA-mRNA also achieved a good therapeutic effect in tumor recurrence inhibition and tumor prophylactic experiments. This study provided a new direction for the design of mRNA vectors, which is promising in tumor immunotherapy.

Intramolecular hydrogen bond-tuned thermal-responsive carbon dots and their application to abnormal body temperature imaging

A steric hindrance strategy was used to prepare intramolecular hydrogen bond-controlled thermosensitive fluorescent carbon dots (CDs) via the solvothermal treatment of o-phenylenediamine respectively with three dihydroxybenzene isomers. The CDs obtained from different isomers have very similar morphology, surfaces, and photophysical properties but exhibited different thermal sensitivities. Meanwhile, the orange-emitting CDs (p-CDs) obtained from o-phenylenediamine and p-hydroquinone exhibited an optimal thermal sensitivity of 1.1%/°C. Comprehensive experimental characterizations and theoretical calculations revealed that even a small difference in substituent locations in the phenyl ring of the precursors can considerably affect the formation of intramolecular hydrogen bonds and that the CDs with strong intramolecular hydrogen bonds exhibited poor thermosensitivity. The p-CDs were incorporated with reference CDs (B-CDs) that exhibited heating-quenching blue emission through electrostatic self-assembly to construct a dual-emission probe (p-CDs/B-CDs), which exhibited a thermal sensitivity of 2.0%/°C. Test strips based on the p-CDs/B-CDs were prepared to measure temperature fluctuations based on sensitive and instant fluorescence color evolution. Further, this fluorescent colorimetry was successfully applied to a test strip-integrated wearable wristband to measure the body temperature. This study establishes an inherent relationship between precursors and the resulting intramolecular hydrogen bonds for precisely tuning the thermal sensitivity of CDs. It also offers a visual quantitative strategy for the early warning of abnormal body temperatures.

Construction of a ratiometric fluorescent probe for visual detection of urea in human urine based on carbon dots prepared from Toona sinensis leaves and 5-carboxyfluorescein

In this work, pH-sensitive blue fluorescent carbon dots (CDs) with high fluorescence quantum yield (17.24%) were synthesized by hydrothermal method using Toona sinensis leaves and ethylenediamine (EDA) as raw materials. The CDs can detect urea with a limit of detection (LOD) of 6.700 mmol L^-1. For more sensitive detection of urea, we constructed a ratiometric fluorescent probe (CDs@5-FAM) using CDs and 5-carboxyfluorescein (5-FAM). The CDs@5-FAM probe can rapidly and sensitively detect urea according to the changes of I₅₁₄/I₄₀₅, with LOD as low as 0.014 mmol L^-1. Furthermore, with the help of a smartphone and RGB analysis software, urea's visual intelligent detection was realized using a CDs@5-FAM probe. The method proposed in this paper is consistent with the standard method, which indicates that the pH-sensitive ratiometric fluorescent probe CDs@5-FAM is accurate and reliable for practical application. It provides a new way for rapid and visual detection of urea.

Progress and Prospects of Electrochemiluminescence Biosensors Based on Porous Nanomaterials

Porous nanomaterials have attracted much attention in the field of electrochemiluminescence (ECL) analysis research because of their large specific surface area, high porosity, possession of multiple functional groups, and ease of modification. Porous nanomaterials can not only serve as good carriers for loading ECL luminophores to prepare nanomaterials with excellent luminescence properties, but they also have a good electrical conductivity to facilitate charge transfer and substance exchange between electrode surfaces and solutions. In particular, some porous nanomaterials with special functional groups or centered on metals even possess excellent catalytic properties that can enhance the ECL response of the system. ECL composites prepared based on porous nanomaterials have a wide range of applications in the field of ECL biosensors due to their extraordinary ECL response. In this paper, we reviewed recent research advances in various porous nanomaterials commonly used to fabricate ECL biosensors, such as ordered mesoporous silica (OMS), metal-organic frameworks (MOFs), covalent organic frameworks (COFs) and metal-polydopamine frameworks (MPFs). Their applications in the detection of heavy metal ions, small molecules, proteins and nucleic acids are also summarized. The challenges and prospects of constructing ECL biosensors based on porous nanomaterials are further discussed. We hope that this review will provide the reader with a comprehensive understanding of the development of porous nanomaterial-based ECL systems in analytical biosensors and materials science.

Internal dual-emissive carbon dots for double signal detection of procainamide

We fabricated an internal dual-emission carbon dots using a facile hydrothermal treatment of eosin Y and ethylenediamine (EDA). The Y-CDs exhibit distinct double peaks at 384 and 520 nm on...