A transcription factor-based bacterial biosensor system and its application for on-site detection of explosives

Cell-free biosensor with automated acoustic liquid handling for rapid and scalable characterization of cellobiohydrolases on microcrystalline cellulose

Engineering enzymes to degrade solid substrates, such as crystalline cellulose from paper sludge or microplastics in sewage sludge, presents challenges for high-throughput screening (HTS), as solid substrates are not readily accessible in cell-based biosensor systems. To address this challenge, we developed a cell-free cellobiose-detectable biosensor (CB-biosensor) for rapid characterization of cellobiohydrolase (CBH) activity, enabling direct detection of hydrolysis products without cellular constraints. The CB-biosensor demonstrates higher sensitivity than conventional assays and distinguishes between CBH subtypes (CBHI and CBHII) based on their modes of action. Integration with the Echo 525 liquid handler enables precise and reproducible sample processing, with fluorescence signals from automated preparations comparable to manual experiments. Furthermore, assay volumes can be reduced to just a few microlitres-impractical with manual methods. This cell-free CB-biosensor with Echo 525 minimizes reagent consumption, accelerates testing, and facilitates reliable large-scale screening. These findings highlight its potential to overcome current HTS limitations, advancing enzyme screening and accelerating the Design-Build-Test-Learn cycle for sustainable biomanufacturing.

Machine Learning-Assisted Portable Dual-Readout Biosensor for Visual Detection of Milk Allergen

Beta-lactoglobulin (β-LG), the primary allergen in cow's milk, makes developing a rapid, sensitive, and convenient detection method essential for individuals with allergies. In this study, a graphdiyne-based self-powered electrochemical biosensor has been cleverly integrated into the corresponding test strip. This biosensor uses glucose as fuel and correlates the β-LG concentration with the glucose value displayed on a mobile phone application, enabling real-time and quantitative detection. Additionally, an electrochromic substance reacts with the byproduct (H2O2) of glucose oxidation by biological enzymes. A quantitative relationship between color and β-LG concentration has been established using mobile phone software. Dual detection of electrochemical and colorimetric signals in the 0.01-10,000 ng/mL range, with detection limits as low as 0.0033 and 0.0081 ng/mL, is possible. Machine learning is finally employed to analyze its performance. Our dual-readout biosensor demonstrates significant potential for rapid food allergy detection.

Fabric-based visualization biosensor for real-time environmental monitoring and food safety

Foodborne and waterborne bacterial infections caused by Escherichia coli (E. coli) pose a serious threat to public health and safety. Therefore, there is an urgent need to develop a fast and accurate diagnostic device for early detection and prevention of bacterial contamination. In this study, we designed a visual cotton fabric-based detection biosensor that can target enzymes produced by E. coli metabolism and induce color changes. In addition, the system can be integrated with the naked eye, smartphones, and small spectrometers to analyze the generated signals for qualitative, semi-quantitative, and quantitative detection. The platform achieved a minimum detection limit of 537 cfu/mL for E. coli, a wide detection range of 102-106 cfu/mL, and a minimum detection time as low as 20 mins. The detection results of complex environmental samples showed that the system has excellent anti-ion interference and anti-pH interference behavior. This visual detection biosensor has great commercial application potential and can be widely used in real-time on-site detection due to its rapid, portable, anti-interference, and low-cost advantages.

A sensitive PnpR-based biosensor for p-nitrophenol detection

A common aromatic and phenolic pollutant, p-nitrophenol (PNP), is widely used in various industry and has serious risk to the environmental health. Biosensors have been extensively employed as an alternative technology for pollutants monitoring. By mining the new sensing elements, more specific biosensors could be characterized for highly sensitive detection. Herein, the PnpR transcription factor was identified to activate the transcription of pnpC1 by binding to PpnpC1 promoter region in P. putida DLL-E4, and PNP was recognized as its specific inducer. The PnpR-based biosensor for detection of PNP was developed, demonstrating adequate sensitivity in a liquid solution with satisfactory specificity. The biosensor was optimized by adopting a transcriptional amplifier, which increased the maximum output by 149-fold, and improved the detection limit by 100-fold, from 1 mg/L to 10 μg/L. These biosensors had a linear range of 5-80 mg/L and 0.01-1.0 mg/L for PNP determination, respectively. Then, the agarose gel entrapment-based biosensor was constructed and allowed a good of PNP detection in the range of 5-60 mg/L in M9 solid agar within 70 min, and a detection sensitive of 16.8 mg/kg in soil. The good performance of the biosensor suggested its potential application of high-efficient and on-site detection in environmental matrices.

E. coli-Assisted Eco-Friendly Production of Biogenic Silver Cobalt Oxide (AgCoO2 ) Nanoparticles: Methanolysis-Based Hydrogen Production, Wastewater Remediation, and Pathogen Control

Herein, bacterial-assisted synthesis of AgCoO2 is carried out. In the first step, E. coli was separated from soil samples via the "serial dilution method." Ten milliliters of bacterial supernatant was mixed with cobalt chloride and silver nitrate hatched at 38°C for 24 h to get AgCoO2 nanoparticles (NPs). XRD results confirm the synthesis of AgCoO2 NPs while EDX results confirm the absence of any other elements than Ag, Co, and O. An average NP size of 12-26 nm was determined by TEM examination, and the surface of the particles was seen rough, irregularly shaped borders. The antibacterial activity of the constructed NPs was checked against S. aureus, E. coli, Bacillus subtilus, and Pseudomanas areguinosa using agar well diffusion method. The maximum zone of inhibition was 27 mm at 40 mg/mL against Bacillus subtilus. The performance of the synthesized NPs as photocatalysts was also assessed, and several operational parameters that control the photodegradation of the harmful dyes were tried to tune as well, and 85% degrading efficiency was obtained at 60oC for 240 min for 30 mg of catalyst dose These NPs were also used to produce hydrogen by methanolysis.

Flexible Nanostructured NiS-Based Electrochemical Biosensor for Simultaneous Detection of DNA Nucleobases

Herein, we demonstrate a one-step, scalable, solution-processed method for the growth of nickel sulfide (NiS) nanostructures using single-source precursors (SSPs) on a flexible substrate as a versatile framework for simultaneous detection of four DNA nucleobases. The as-grown NiS nanostructures exhibit a broad bandgap range and spherical morphology with high surface area and significant porosity, as confirmed by SEM, TEM, and BET surface area analysis. Consequently, the NiS/Ni-foam electrode exhibited remarkable electrochemical performance toward the oxidation of A, G, T, and C due to its large surface area, high electrode activity, and efficient electron transfer capacity. Under the optimum conditions, the electrode demonstrated selective and simultaneous detection of all four nucleobases over a wide linear range from 200 to 1000 μM for A and G, and 50 to 500 μM for T and C, with a low limit of detection of 159 μM for A, 147.6 μM for G, 16.8 μM for T, and 45.9 μM for C, along with high sensitivity of 1.2 × 10-4 A M-1 for A, 6.1 × 10-4 A M-1 for G, 1.2 × 10-3 A M-1 for T, and 3.0 × 10-4 A M-1 for C. The as-fabricated electrode revealed excellent reproducibility and stability toward nucleobase detection and demonstrated a reliable DPV response under different bending and twisting conditions. For immediate practical application, NiS/Ni-foam was utilized to quantify the concentration of all nucleobases in calf thymus and Escherichia coli (E. coli) DNA, resulting in a (G + C)/(A + T) ratio of 0.79 and 1.10, respectively. This simple, cost-effective, and flexible NiS/Ni-foam electrode paves the way for the development of non-invasive, wearable biosensors for potential applications in early disease detection.

Therapeutic Innovations in Nanomedicine: Exploring the Potential of Magnetotactic Bacteria and Bacterial Magnetosomes

Nanotechnology has emerged as a revolutionary domain with diverse applications in medicine, and one of the noteworthy developments is the exploration of bacterial magnetosomes acquired from magnetotactic bacteria (MTB) for therapeutic purposes. The demand for natural nanomaterials in the biomedical field is continuously increasing due to their biocompatibility and eco-friendly nature. MTB produces uniform, well-ordered magnetic nanoparticles inside the magnetosomes, drawing attention due to their unique and remarkable features. MTB and magnetosomes have gained popularity in cancer treatment and diagnosis, especially in magnetic resonance imaging. Distinctive features highlighted include advancements in extraction, characterization, and functionalization techniques, alongside breakthroughs in utilizing MTB-based magnetosomes as contrast agents in imaging, biocompatible drug carriers, and tools for minimally invasive therapies. The biocompatible nature, functionalizing of the surface of bacterial magnetosomes, and response to the external magnetic field make them a potential candidate for the theragnostic purpose of MTB and magnetosomes. In the present review, emphasis has been given to the foundation of magnetosomes at a genetic level, mass production of magnetosomes, etc. Further authors have reviewed the various functionalization methods of the magnetosomes for cancer treatment. Finally, the authors have reviewed the recent advancements in MTB and magnetosome-based cancer detection, diagnosis, and treatment. Challenges such as scalability, long-term safety, and clinical translation are also discussed, presenting a roadmap for future research exploiting MTBs and magnetosomes' unique properties.

DFT study of the adsorption properties and sensitivity of a B2N monolayer toward harmful gases

In this study, we investigate the adsorption of harmful gases - CO, NO, NO2, SO2, and O3 molecules - on a B2N monolayer using periodic density functional theory. The adsorption energy values for the CO/B2N, NO/B2N, NO2/B2N, SO2/B2N, and O3/B2N complexes are determined to be -1.96, -1.39, -1.80, -0.70, and - 2.36 eV, respectively. The B2N monolayer has the ability to adsorb harmful gas molecules, even in humid air, and displays favorable adsorption energy and standard recovery time when exposed to SO2 gas. Consequently, the impact of SO2 gases on the transmission characteristics of the B2N monolayer has been assessed through current-voltage analysis. These findings are of great importance as they serve to demonstrate the remarkable sensing capabilities of a B2N monolayer in efficiently detecting SO2 gas. The desorption time for CO, NO, NO2, and O3 molecules is quite long, thereby indicating the remarkable stability of the B2N sheet for adsorption of these gases. The current study offer valuable insights for further research into the potential utilization of B2N monolayers in long-term monitoring and gas purification applications, specifically in relation to four toxic gases: CO, NO, NO2, and O3.

Efficient detection of carbendazim using an electrochemical sensor for a novel NiFeLDH@HsGY-NH2/MWCNTs heterostructure with lattice-strain

Carbendazim (CBZ) is widely used for crop protection and its residues threaten human health and the environment. Therefore, developing an effective electrocatalyst is important for the extremely sensitive detection of CBZ. Lattice-strain engineering is an effective strategy to change its electronic structure and ultimately optimize the catalytic performance of materials, which can be used as a modification method to improve the detection performance of electrochemical sensors. Herein, a NiFeLDH@HsGY-NH2/MWCNTs heterojunction with strain effect is prepared by the electrostatic self-assembly method. The structure, morphology, composition, crystallinity and electrochemical performance of NiFeLDH@HsGY-NH2/MWCNTs are analyzed using various instrumental techniques, in which geometric phase analysis (GPA) and X-ray diffraction (XRD) images confirm the lattice-strain generated in NiFeLDH@HsGY-NH2/MWCNTs. The results indicate that the prepared electrochemical sensor exhibited an excellent response for carbendazim (CBZ) in the linear range of 0.05-50.00 μM with a detection limit of 10.00 nM (S/N = 3) under the optimal detection conditions. By analyzing the reasons for the improvement of the catalytic performance of the composite material, it is found that the composite of MWCNTs not only improves the conductivity of NiFeLDH but also regulates the electronic structure of metal atoms through double effects. This study provides new insights into the design of efficient and low-cost catalysts to facilitate electrochemical sensor applications.

Laser-Induced Graphene for Advanced Sensing: Comprehensive Review of Applications

Laser-induced graphene (LIG) and Laser-scribed graphene (LSG) are both advanced materials with significant potential in various applications, particularly in the field of sustainable sensors. The practical uses of LIG (LSG), which include gas detection, biological process monitoring, strain assessment, and environmental variable tracking, are thoroughly examined in this review paper. Its tunable characteristics distinguish LIG (LSG), which is developed from accurate laser beam modulation on polymeric substrates, and they are essential in advancing sensing technologies in many applications. The recent advances in LIG (LSG) applications include energy storage, biosensing, and electronics by steadily advancing efficiency and versatility. The remarkable flexibility of LIG (LSG) and its transformative potential in regard to sensor manufacturing and utilization are highlighted in this manuscript. Moreover, it thoroughly examines the various fabrication methods used in LIG (LSG) production, highlighting precision and adaptability. This review navigates the difficulties that are encountered in regard to implementing LIG sensors and looks ahead to future developments that will propel the industry forward. This paper provides a comprehensive summary of the latest research in LIG (LSG) and elucidates this innovative material's advanced and sustainable elements.

Biophysical translational posterity of green carbon quantum dots: the unparalleled versatility

Carbon dots (CQDs), zero-dimensional carbon nanostructures, have attracted considerable interest among researchers due to their versatile applications. CQDs exhibit exceptional photoluminescent properties and high quantum yield, making them ideal candidates for bioimaging, drug delivery and environmental sensing. Their biocompatibility and tunable surface chemistry enable targeted therapeutic delivery and real-time imaging with minimal toxicity. Additionally, CQDs are emerging as promising materials in optoelectronics, offering sustainable alternatives in light-emitting diodes and solar cells. This review underscores the unparalleled adaptability of green CQDs in bridging the gap between laboratory research and practical applications, paving the way for innovative solutions in healthcare and environmental monitoring. Through comprehensive analysis, it advances the understanding of CQDs, positioning them at the forefront of next-generation nanomaterials with significant translational impact.

CRISPR-Driven Biosensors: A New Frontier in Rapid and Accurate Disease Detection

This comprehensive review delves into the advancements and challenges in biosensing, with a strong emphasis on the transformative potential of CRISPR technology for early and rapid detection of infectious diseases. It underscores the versatility of CRISPR/Cas systems, highlighting their ability to detect both nucleic acids and non-nucleic acid targets, and their seamless integration with isothermal amplification techniques. The review provides a thorough examination of the latest developments in CRISPR-based biosensors, detailing the unique properties of CRISPR systems, such as their high specificity and programmability, which make them particularly effective for detecting disease-associated nucleic acids. While the review focuses on nucleic acid detection due to its critical role in diagnosing infectious diseases, it also explores the broader applications of CRISPR technology in detecting non-nucleic acid targets, thereby acknowledging the technology's broader potential. Additionally, the review identifies existing challenges, such as the need for improved signal amplification and real-world applicability, and offers future perspectives aimed at overcoming these hurdles. The ultimate goal is to advance the development of highly sensitive and specific CRISPR-based biosensors that can be used widely for improving human health, particularly in point-of-care settings and resource-limited environments.

A novel strategy for the synthesis of samarium/europium-metal organic frameworks, and their utilization for detection of Cr3+, Pb2+, and acetone as a luminescent sensor with superior selectivity and sensitivity properties

With outstanding detection selectivity and sensitivity characteristics, samarium/europium-metal organic frameworks (Sm/Eu-MOF) is capable of functioning as a versatile light-emitting sensor particularly for detecting acetone, Cr3+, and Pb2+ in aqueous environment. While considering maximum detectable concentrations of 0.85 μM, 0.46 μM, and 1.04 μM, respectively, competitive energy interactions for acetone, absorption of energy for Cr3+, and substitution of ions for Pb2+ are the elucidated mechanisms of detecting these substances by Sm/Eu-MOF. Successful formulation and synthesis of a core-shell structured Sm/Eu-MOF, which has endurance to acid/alkali conditions and hydration/heat-stability, can be accomplished by utilizing Samarium and Europium nitrate ions, terephthalic acid, and 2, 5-furandicarboxylic acid. The recovery rate of acetone, Cr3+, and Pb2+ detection from real samples were 95.0-101.0 %, 99.8-101.0 %, and 99.9-104.0 %, respectively.

2D Materials in Advanced Electronic Biosensors for Point-of-Care Devices

Since two-dimensionalal (2D) materials have distinct chemical and physical properties, they are widely used in various sectors of modern technologies. In the domain of diagnostic biodevices, particularly for point-of-care (PoC) biomedical diagnostics, 2D-based field-effect transistor biosensors (bio-FETs) demonstrate substantial potential. Here, in this review article, the operational mechanisms and detection capabilities of biosensing devices utilizing graphene, transition metal dichalcogenides (TMDCs), black phosphorus, and other 2D materials are addressed in detail. The incorporation of these materials into FET-based biosensors offers significant advantages, including low detection limits (LOD), real-time monitoring, label-free diagnosis, and exceptional selectivity. The review also highlights the diverse applications of these biosensors, ranging from conventional to wearable devices, underscoring the versatility of 2D material-based FET devices. Additionally, the review provides a comprehensive assessment of the limitations and challenges faced by these devices, along with insights into future prospects and advancements. Notably, a detailed comparison of FET-based biosensors is tabulated along with various other biosensing platforms and their working mechanisms. Ultimately, this review aims to stimulate further research and innovation in this field while educating the scientific community about the latest advancements in 2D materials-based biosensors.

Advanced protein nanobiosensors to in-situ detect hazardous material in the environment

Determining hazardous substances in the environment is vital to maintaining the safety and health of all components of society, including the ecosystem and humans. Recently, protein-based nanobiosensors have emerged as effective tools for monitoring potentially hazardous substances in situ. Nanobiosensor detection mode is a combination of particular plasmonic nanomaterials (e.g., nanoparticles, nanotubes, quantum dots, etc.), and specific bioreceptors (e.g., aptamers, antibodies, DNA, etc.), which has the benefits of high selectivity, sensitivity, and compatibility with biological systems. The role of these nanobiosensors in identifying dangerous substances (e.g., heavy metals, organic pollutants, pathogens, toxins, etc.) is discussed along with different detection mechanisms and various transduction methods (e.g., electrical, optical, mechanical, electrochemical, etc.). In addition, topics discussed include the design and construction of these sensors, the selection of proteins, the integration of nanoparticles, and their development processes. A discussion of the challenges and prospects of this technology is also included. As a result, protein nanobiosensors are introduced as a powerful tool for monitoring and improving environmental quality and community safety.

Immobilization of Bacillus thuringiensis Cry1Ac in metal-organic frameworks through biomimetic mineralization for sustainable pest management

Traditional chemical pesticide dosage forms and crude application methods have resulted in low pesticide utilization, increased environmental pollution, and the development of resistance. Compared to traditional pesticides, nanopesticides enhance the efficiency of pesticide utilization and reduce the quantity required, thereby decreasing environmental pollution. Herein, Cry1Ac insecticidal crystal protein from Bacillus thuringiensis Subsp. Kurstaki HD-73 was encapsulated in a metal-organic framework (zeolite imidazolate framework-8, ZIF-8) through biomimetic mineralization to obtain Cry1Ac@ZIF-8 nanopesticides. The Cry1Ac@ZIF-8 nanopesticides exhibited a dodecahedral porous structure, and the introduction of Cry1Ac did not affect the intrinsic crystal structure of ZIF-8. The indoor toxicity analysis revealed that the toxicity of Cry1Ac towards Ostrinia furnacalis (Guenée), Helicoverpa armigera Hubner, and Spodoptera litura Fabricius was not affected by ZIF-8 encapsulation. Surprisingly, Cry1Ac@ZIF-8 still exhibited excellent pest management efficacy even after exposure to heat, UV irradiation, and long-term storage. More importantly, the encapsulation of ZIF-8 significantly enhanced the internal absorption performance of Cry1Ac in maize leaves and extended its persistence period. Thus, ZIF-8 could potentially serve as a promising carrier for the preparation of nanopesticides with enhanced applicability, stability, and persistence period, providing a powerful strategy to improve the application of Cry1Ac in future agricultural pest management.

Tyrosinase-based nanobiosensor for environmental monitoring of hormones in river water

This study explores the application of a tyrosinase cantilever nanobiosensor for detecting 17β-estradiol and estrone in typical water systems. The physical-chemical parameters of water were evaluated within the Tigre River micro-basin in Erechim, RS, to determine water potability for urban populations. Water clarity, conductivity, and pH levels were essential markers, adhering to recognized standards for water quality and human consumption. The cantilever nanobiosensor demonstrated strong sensitivity and a broad linear range, with a limit of detection (<0.00051 ppb) surpassing other enzymatic biosensors and covering a range of 0.0001-100 ppb. The real water sample quality investigated in relation to contamination with 17β-estradiol and estrone by nanobiosensor showed values below the LOD for both compounds. Recovery studies demonstrated the reliability of the nanobiosensor. Selectivity tests indicated minimal interference from structurally similar substances. This study validates the nanobiosensor's potential for environmental monitoring and hormone detection, aligning with standard practices.

Assessing the gas sensing capability of undoped and doped aluminum nitride nanotubes

CONTEXT

CO2 and CO gas sensors are very important to recognize the insulation situation of electrical tools. ToCO explore the application of noble metal doped of aluminum nitride nanotubes for gas sensors, DFT computations according to the first principal theory were applied to study sensitivity, adsorption attributes, and electronic manner. In this investigation, platinum-doped aluminum nitride nanotubes were offered for the first time to analyze the adsorption towards CO2 and CO gases. Firm construction of platinum-doped aluminum nitride nanotubes (Pt-AlNNT) was investigated in four feasible places, and the binding energy of firm construction is 1.314 eV. Respectively, the adsorption energy between the CO2 and Pt-AlNNT systems was - 2.107 eV, while for instance of CO, the adsorption energy was - 3.258 eV. The mentioned analysis and computations are considerable for studying Pt-AlNNT as a new CO2 and CO gas sensor for electrical tools insulation. The current study revealed that the Pt-AlNNT possesses high selectivity and sensitivity towards CO2 and CO.

METHODS

In this research, Pt-doped AlNNT (Pt-AlNNT) has been studied as sensing materials of CO and CO2 for the first time. The adsorption process of Pt-AlNNT has been computed and analyzed through the DFT approach. DFT computations by using B3LYP functional and 6-31 + G* basis sets have been applied in the GAMESS code for sensing attributes, which contribute to potential applications.

Isolation, characterization and anti-inflammatory activity of compounds from the Vernonia amygdalina

The need to explore the abundance of natural products cannot be overemphasized particularly in the management of various disease conditions. In traditional medical practice, Vernonia amygdalina has been widely adopted in the management of various inflammatory disorders. The objective of this investigation was to isolate the bioactive principles from the stem-bark and root of V. amygdalina and assess the anti-inflammatory (in vitro) activity of both the crude extracts and the isolated compounds. Following extraction with the methanol, the extract was subjected to gravity column chromatography and the resultant fractions was further purified to obtained pure compounds. The structural elucidation of the compounds were based on data obtained from 1H to 13C nuclear magnetic resonance (NMR) spectroscopies as well as fourier transform infrared (FT-IR). Using diclofenac as a control drug, the albumin denaturation assay was used to determine the in vitro anti-inflammatory activity of the extracts and isolates. Three distinct compounds characterized are vernoamyoside D, luteolin-7-α-o-glucuronide, and vernotolaside, a new glycoside. When compared to diclofenac, which has an IC50 of 167.8 μg/mL, luteolin-7-α-o-glucuronide, vernoamyoside D, and vernotolaside all showed significant inhibitions with respective IC50 values 549.8, 379.5, and 201.7 μg/mL. Vernotolaside is reported for the first time from the root. The assertion that the plant is used in traditional medicine for the management of inflammatory disorder is somewhat validated by the confirmation of the existence of the compounds with the biochemical actions. Further validation of the isolated compounds would be required in animal studies.