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Exosomes are critical tumor biomarkers, which can be detected by label‐free sensing of plasmonic metasurfaces with expensive antibody functionalization. Due to their low cost and small size, aptamers should be promising to replace antibodies in plasmonic metasensing of exosomes. However, research on aptamer‐based plasmonic metasensing of exosomes is still unexplored. Here, the optical near‐field sensing mechanism of aptamer‐based plasmonic metasurface (APM) is investigated. Based on the study of the evanescent field of APM, using thiol‐modified aptamer boosts the utilization rate of resonance wavelength shift from 27.5% to 83.3% compared to biotinylated aptamers, attributed to a significant reduction in the near‐field occupation of the biofunction layer. Moreover, APM biosensors effectively detect clinical serum exosomes for breast cancer (BC) diagnosis and classification. The receiver operating characteristic analysis shows an area under the curve of 99.3% for APM diagnosis, surpassing the 79.1% for hematological tests of the conventional BC biomarker CA153. The results also indicate that APM biosensors can be a noninvasive tool for molecular classification of BC with great distinguishment of P < 0.0001. The research demonstrates that APM biosensors are enabling a reliable and convenient platform to facilitate clinical hematological tests of exosomes for auxiliary diagnosis of cancer. [ABSTRACT FROM AUTHOR]

Summary: Gelatine is obtained from the hydrolysis of collagen in bones, skin, fins, fish scales and insect bodies of cattle, pigs, camels, poultry, fish and insects. Consequently, the diversity and availability of gelatine sources, along with gelatine authentication, are concerns for those consuming gelatine products from religious, health and economic perspectives. Therefore, rapid and reliable protein‐ or DNA‐based detection methods have been developed for gelatine authentication. This review discusses and evaluates biosensor methods, comparing them with various analytical methods in terms of their popularity and precision. Additionally, the development of biosensor methods has been explored to identify a reference for a rapid, accurate, portable and simple method for gelatine detection with a low detection limit and high specificity. [ABSTRACT FROM AUTHOR]

As widely used commercial sensors, amperometric biosensors based on electrochemical (EC) reactions exhibit good linearity and reproducibility but suffer from a low dynamic range and poor limit of detection (LoD). In contrast, biosensors utilizing field‐effect transistors (FETs) demonstrate a wide detection range and ultralow LoDs but are susceptible to interferences or ionic strength influences and have poor quantitative accuracy due to their nonlinear response mechanism. Here, EC and carbon nanotube (CNT) FET‐based biosensors are integrated into one chip via a compatible fabrication process. The dual‐mode biosensing chip (DMSC) provides the advantages from both the EC biosensors and FET biosensors; these advantages include high reliability and accuracy for quantitatively detecting glucose, a dynamic detection range spanning 6 orders of magnitude, and a detection limit of 1 fM. The introduction of a time‐division multiplexing detection method enables the DMSC to carry out complementary detection of the same target, providing early warning of specific abnormal biomarkers and accurate determination of their concentration in real time. The DMSC approach is generally applicable to the detection of other biomarkers and provides exciting opportunities for more accurate self‐monitoring diagnostics in real situations. [ABSTRACT FROM AUTHOR]

l‐2‐Hydroxyglutarate (l‐2‐HG) is a functionally compartmentalized metabolite involved in various physiological processes. However, its subcellular distribution and mitochondrial transport remain unclear owing to technical limitations. In the present study, an ultrasensitive l‐2‐HG biosensor, sfLHGFRH, composed of circularly permuted yellow fluorescent protein and l‐2‐HG‐specific transcriptional regulator, is developed. The ability of sfLHGFRH to be used for analyzing l‐2‐HG metabolism is first determined in human embryonic kidney cells (HEK293FT) and macrophages. Then, the subcellular distribution of l‐2‐HG in HEK293FT cells and the lower abundance of mitochondrial l‐2‐HG are identified by the sfLHGFRH‐supported spatiotemporal l‐2‐HG monitoring. Finally, the role of the l‐glutamate transporter SLC1A1 in mitochondrial l‐2‐HG uptake is elucidated using sfLHGFRH. Based on the design of sfLHGFRH, another highly sensitive biosensor with a low limit of detection, sfLHGFRL, is developed for the point‐of‐care diagnosis of l‐2‐HG‐related diseases. The accumulation of l‐2‐HG in the urine of patients with kidney cancer is determined using the sfLHGFRL biosensor. [ABSTRACT FROM AUTHOR]

Surface plasmon resonance (SPR) is a key technique in developing sensor platforms for clinical diagnostics, drug discovery, food quality, and environmental monitoring applications. While prism‐coupled (Kretschmann) SPR remains a “gold‐standard” for laboratory work‐flows due to easier fabrication, handling and high through put, other configurations such as grating‐coupled SPR (GC‐SPR) and wave‐guide mode SPR are yet to fulfil their technology potential. This work evaluates the technical aspects influencing the performance of GC‐SPR and reviews recent progress in the fabrication of such platforms. In principle, the GC‐SPR involves the illumination of the plasmonic metal film with periodic gratings to excite the surface plasmons (SP) via diffraction‐based phase matching. The real performance of the GC‐SPR is, however, heavily influenced by the topography of the grating structures produced via top‐down lithography techniques. This review discusses latest in approaches to achieve consistent plasmonic gratings with uniform features and periodicity over a large scale and explores the choice of plasmon‐active and substrate material for enhanced performance. The review also provides insights into the different GC‐SPR measurement configurations and highlights on opportunities with their potential applications as biosensors with translational capabilities. [ABSTRACT FROM AUTHOR]

Stimuli‐responsive polymers have received increasing attention for various applications due to their ability to adapt physical and chemical properties in response to external environmental stimuli. In this regard, poly(N‐isopropylacrylamide) (PNIPAM) is the most extensively studied stimuli‐responsive polymer and, consequently has been prominently featured in (bio)‐sensor development, adaptive coating technology, drug delivery, wound healing, tissue regeneration, artificial actuator design, sensor technology, responsive coatings, and soft robotics. This success can be mainly attributed to the accessible and versatile nature of the PNIPAM platform, thus allowing the synthesis of a wide variety of copolymer architectures, topologies and compositions. Within this review, the structural and compositional features of PNIPAM‐based materials in sensor and biosensor applications are discussed with a focus on the literature from 2016 until now. The reader is provided with the current state of the art regarding PNIPAM‐based sensor development and their molecular design. Finally, the challenges ahead in the successful implementation of PNIPAM‐based sensors are highlighted, as well as the opportunities in the rational design of improved PNIPAM‐based sensors. Altogether, this review provides comprehensive insights into the exciting and rapidly expanding field of PNIPAM‐based sensing systems, which will benefit the chemical, pharmaceutical, textile, and biotech industries is believed. [ABSTRACT FROM AUTHOR]

Recently, the concept of introducing disorder into ordered metasurfaces or periodic metastructures has shown great potential in improving their performance for light extraction, scattering, reflection, and radiation. However, its use in optical biosensing enhancement is still barely reported. Here, a kind of plasmonic biosensors based on disorder‐enhanced nanograin metasurfaces (DENMs) are proposed, and utilized for high‐sensitivity detection of SARS‐CoV‐2 Omicron variant and vaccine‐induced total antibodies. With the aim to elucidate the physics of short‐range‐disordered meta‐elements in long‐range‐ordered metastructures, the meta‐atom evolution is deduced from periodic nanohole metasurfaces to DENMs and totally disordered nanograin metasurfaces. It is found that the disorder of nanograin plays a critical role in elevating the DENM surface sensitivity of biomolecules. The DENM‐based biosensing demonstrates an extremely high diagnostic specificity with the probability P < 0.0001 on distinguishing the Omicron variant from other respiratory viruses. Moreover, these biosensors are used as a convenient tool to monitor vaccine efficacy for inoculators with the third booster injections. This study implies the promise of disorder‐enhanced metasurfaces on biomedical detection and will guide their applications on virus early discovery and prevention for future mobile healthcare. [ABSTRACT FROM AUTHOR]

The extensive use of chemical pesticides has significantly boosted agricultural food crop yields. Nevertheless, their excessive and unregulated application has resulted in food contamination and pollution in environmental, aquatic, and agricultural ecosystems. Consequently, the on‐site monitoring of pesticide residues in agricultural practices is paramount to safeguard global food and conservational safety. Traditional pesticide detection methods are cumbersome and ill‐suited for on‐site pesticide finding. The systematic review provides an in‐depth analysis of the current status and perspectives of nanobiosensors (NBS) for pesticide detection in the agricultural arena. Furthermore, the study encompasses the fundamental principles of NBS, the various transduction mechanisms employed, and their incorporation into on‐site detection platforms. Conversely, the assortment of transduction mechanisms, including optical, electrochemical, and piezoelectric tactics, is deliberated in detail, emphasizing its advantages and limitations in pesticide perception. Incorporating NBS into on‐site detection platforms confirms a vital feature of their pertinence. The evaluation reflects the integration of NBS into lab‐on‐a‐chip systems, handheld devices, and wireless sensor networks, permitting real‐time monitoring and data‐driven decision‐making in agronomic settings. The potential for robotics and automation in pesticide detection is also scrutinized, highlighting their role in improving competence and accuracy. Finally, this systematic review provides a complete understanding of the current landscape of NBS for on‐site pesticide sensing. Consequently, we anticipate that this review offers valuable insights that could form the foundation for creating innovative NBS applicable in various fields such as materials science, nanoscience, food technology and environmental science. [ABSTRACT FROM AUTHOR]

Background: Patients undergoing major oncological abdominal surgery are prone to postoperative complications, making early recognition crucial. Clinical deterioration is often preceded by changes in vital signs, which are typically measured thrice a day by a nurse. However, intermittent measurements may delay recognizing clinical deterioration. Continuous vital parameter monitoring may lead to earlier recognition and management of complications and reduce nursing workload. Objective: To compare vital parameter measurements between ward nurses and a wireless continuous monitoring system (Sensium® wireless patch) and assess whether this patch can detect clinical deterioration earlier in patients with complications in the first postoperative week. Methods: Vital parameters (heart rate, respiratory rate, and temperature) were collected in patients undergoing an oncological resection of the liver, colorectal, or pancreas. Sensium® patch measurements were compared to nurses' measurements to assess the percentages of discordant measurements. In patients with complications in the first postoperative week, time discrepancies between nurses and Sensium® patch measurements were identified in cases of clinical deterioration (respiratory rate ≥15/min, heart rate ≥100/min, and temperature ≥38°C). Results: Among 227 patients, 22% of the patients experienced complications. Nurse and Sensium® measurements were discrepant in 586/2272 measurements (26%). In 506/586 discrepancies (86%), this was due to the respiratory rate (difference ≥4/min). Compared to nurses, the Sensium® patch detected an elevated respiratory rate 14 h earlier and heart rate 2 h earlier within complications in the first postoperative week. For temperature, no difference was observed. Conclusion: Continuous monitoring with the Sensium® wireless patch holds promise for earlier recognition of complications in patients who underwent major oncological abdominal surgery. [ABSTRACT FROM AUTHOR]

Prokaryotic transcription factors (TFs) regulate gene expression in response to small molecules, thus representing promising candidates as versatile small molecule‐detecting biosensors valuable for synthetic biology applications. The engineering of such biosensors requires thorough in vitro and in vivo characterization of TF ligand response as well as detailed molecular structure information. In this work, we functionally and structurally characterize the Pca regulon regulatory protein (PcaR) transcription factor belonging to the IclR transcription factor family. Here, we present in vitro functional analysis of the ligand profile of PcaR and the construction of genetic circuits for the characterization of PcaR as an in vivo biosensor in the model eukaryote Saccharomyces cerevisiae. We report the crystal structures of PcaR in the apo state and in complex with one of its ligands, succinate, which suggests the mechanism of dicarboxylic acid recognition by this transcription factor. This work contributes key structural and functional insights enabling the engineering of PcaR for dicarboxylic acid biosensors, in addition to providing more insights into the IclR family of regulators. [ABSTRACT FROM AUTHOR]

The incidence of thyroid tumors has been increasing yearly over the past decade, making it the fourth highest tumor in women. This places various biological burdens on those affected. Currently, thyroid tumors are primarily diagnosed using percutaneous fine needle aspiration and ultrasound. However, these methods are complex, expensive, and less accurate, and they may fail to detect some thyroid nodules. As an alternative, researchers are focusing on blood‐based biomarkers in addition to the traditional diagnostic methods, assisted predominantly by nanomaterials. Early identification of thyroid cancer is crucial as it is highly treatable. Various sensing systems have been developed using nanomaterial‐mediated approaches to enhance the detection system. Nanomaterials are effectively applied in biosensors for surface functionalization and are conjugated with biomolecules to improve the interaction with the target analyte. This review discusses nanomaterial‐assisted thyroid tumor detection, with a special focus on nanomaterial‐based biosensors. [ABSTRACT FROM AUTHOR]

Silicon‐on‐insulator (SOI) based photonic sensors, particularly those utilizing Photonic Integrated Circuit (PIC) technology, have emerged as promising candidates for miniaturized bioanalytical devices. These sensors offer real‐time responses, occupy minimal space, possess high sensitivity, and facilitate label‐free detection. However, like many biosensors, they face challenges when detecting analytes at exceedingly low concentrations due to limitations in mass transport. An intriguing method to enhance mass transfer in microfluidic biosensors is AC electrokinetics. Proof‐of‐concept experiments have demonstrated significant enhancements in limit of detection (LOD) and response times. AC electrokinetics, compatible with silicon photonic sensors, offers techniques such as electroosmosis, electrothermal effects, and dielectrophoresis to modify fluid flow and manipulate particle trajections. This article delves into various approaches for integrating AC electrokinetics into silicon photonic biosensors, shedding light on both its advantages and limitations. [ABSTRACT FROM AUTHOR]

While levodopa (L‐Dopa) is the primary treatment for alleviating Parkinson's disease (PD), its efficacy is hindered by challenges such as a short half‐life and inconsistent plasma levels. As PD progresses, the rising need for increased and more frequent L‐Dopa doses coupled with symptom fluctuations and dyskinesias underscores the urgency for improved comprehension of the interplay between L‐Dopa levels and PD motor symptoms. Addressing this critical need, we present a decentralized testing method using a disposable biosensor strip and a universal slope (U‐slope) calibration‐free approach. This enables reliable, rapid, simple, and cost‐effective decentralized L‐Dopa measurements from capillary blood. A pilot study with PD persons demonstrates the ability to monitor real‐time L‐Dopa pharmacokinetics from fingerstick blood after oral L‐Dopa‐Carbidopa (C–Dopa) tablet administration. Correlating capillary blood L‐Dopa levels with PD motor scores revealed a well‐defined inverse correlation with temporal motor fluctuations. We compared the resulting dynamic capillary blood L‐Dopa levels with plasma L‐Dopa levels using the traditional but clinically impractical high‐performance liquid chromatography technique. By providing timely feedback on a proper L‐Dopa dosing regimen in a decentralized and rapid fashion, this new biosensing platform will facilitate tailored optimal L‐Dopa dosing, towards improving symptom management and enhancing health‐related quality of life. [ABSTRACT FROM AUTHOR]

Low temperatures are a key condition for various phytopathogenic bacteria, by favouring their pathogenic potential and the development of plant diseases. So far, the signal transduction pathways related to low temperatures in phytopathogenic bacteria are little understood. The occurrence of intracellular oxidative stress under this condition has been suggested as a molecular event belonging to this signalling pathway. In this study, using the Pseudomonas savastanoi pv. phaseolicola model bacteria, we evaluated intracellular redox state under low‐temperature (18°C) conditions. Generation of an oxidative‐stress biosensor (pKL1) and fluorometry analyses with the P. savastanoi pv. phaseolicola‐roGFP2 bioreporter strain were performed. At low temperatures (18°C) the response capacity or roGFP2 oxidation diminished in relation to 28°C. Likewise, changes in the intracellular redox potential of P. savastanoi pv. phaseolicola during its growth at 28°C and 18°C were observed, with greater oxidation degree in cells grown at 18°C. These results demonstrated that low temperatures induce intracellular oxidative stress in P. savastanoi pv. phaseolicola. From this study, the oxidative stress is established as part of the cellular response to low‐temperature conditions in this bacteria. This is the first report of the relation of oxidative stress with low‐temperature conditions in phytopathogens bacteria. [ABSTRACT FROM AUTHOR]

BACKGROUND: This study focuses on the fabrication of a biosensor for the electrocatalytic and selective hydrogen peroxide (H2O2) recognition with bovine liver catalase (CAT) immobilized over a cysteine (c) modified zinc oxide nanoparticles/graphene oxide (c‐ZnO/GO) interface. The selectivity and sensitivity of the biosensor were augmented by the use of CAT and GO, respectively. The problem of CAT activity inhibition by GO was specifically solved by the incorporation of ZnO. Also, the cystine functionalization helped in better immobilization of CAT. RESULTS: This unique approach was first validated with in silico computations that calculated the binding affinities to study the interactions between different components of the biosensor. The electrochemical studies confirmed the step‐by‐step modification of the sensor, where along with GO, c‐ZnO nanoparticles also showed excellent electro‐conductivity by fundamentally improving the peak currents towards H2O2. The proposed bio‐nano interface exhibited superb electrocatalytic performance and specific detection capability for H2O2 across a broad linear range (0.1 to 40 μmol L−1), featuring a low detection limit (0.1 μmol L−1), as well as commendable reproducibility and storage durability. Furthermore, the biosensor yielded satisfactory outcomes for H2O2 detection in milk samples. CONCLUSION: Sensing performance of nano‐bio interfaces can be augmented by using the appropriate nano‐composites and their efficacy confirmed through computational techniques such as molecular docking. The biosensor can be further repurposed into a wearable device by integration with lab‐on‐a‐chip platforms. © 2024 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

L‐cysteine is an important sulfur‐containing amino acid being difficult to produce by microbial fermentation. Due to the lack of high‐throughput screening methods, existing genetically engineered bacteria have been developed by simply optimizing the expression of L‐cysteine‐related genes one by one. To overcome this limitation, in this study, a biosensor‐based approach for multilevel biosynthetic pathway optimization of L‐cysteine from the DecR regulator variant of Escherichia coli was applied. Through protein engineering, we obtained the DecRN29Y/C81E/M90Q/M99E variant‐based biosensor with improved specificity and an 8.71‐fold increase in dynamic range. Using the developed biosensor, we performed high‐throughput screening of the constructed promoter and RBS combination library, and successfully obtained the optimized strain, which resulted in a 6.29‐fold increase in L‐cysteine production. Molecular dynamics (MD) simulations and electrophoretic mobility shift analysis (EMSA) showed that the N29Y/C81E/M90Q/M99E variant had enhanced induction activity. This enhancement may be due to the increased binding of the variant to DNA in the presence of L‐cysteine, which enhances transcriptional activation. Overall, our biosensor‐based strategy provides a promising approach for optimizing biosynthetic pathways at multiple levels. The successful implementation of this strategy demonstrates its potential for screening improved recombinant strains. [ABSTRACT FROM AUTHOR]

High hydrostatic pressure stabilized galactose oxidase (GaOx) at 70.0–80.0°C against thermal inactivation. The pseudo‐first‐order rate constant of inactivation kinact decreased by a factor of 8 at 80°C and by a factor of 44 at 72.5°C. The most pronounced effect of pressure was at the lowest studied temperature of 70.0°C with an activation volume of inactivation ΔV‡ of 78.8 cm3 mol−1. The optimal pressure against thermal inactivation was between 200 and 300 MPa. Unlike other enzymes, as temperature increased the ΔV‡ of inactivation decreased, and as pressure increased the activation energy of inactivation Eai increased. Combining the results for GaOx with earlier research on the pressure‐induced stabilization of other enzymes suggests that ΔV‡ of inactivation correlates with the total molar volume of cavities larger than ~100 Å3 in enzyme monomers for enzymes near the optimal pH and whose thermal unfolding is not accompanied by oligomer dissociation. [ABSTRACT FROM AUTHOR]

Gestational diabetes (GD) is a condition characterized by elevated blood sugar levels during pregnancy. GD poses various health risks, such as serious birth injuries, the need for cesarean delivery, and the necessity of newborn care. Monitoring glucose levels is essential for ensuring safe delivery and reducing the risks to both the mother and fetus. Various sensors are readily available for monitoring glucose levels, and researchers are continually working to develop highly sensitive glucose sensors. This research aimed to develop a gold nanourchin (AuNU)‐hybrid biosensor for quantifying glucose on a multi‐point electrode sensor. Glucose oxidase (GOx) was attached to the AuNU and seeded on the sensing surface using an amine linker. The current‐potential (1–2 V at 0.1 V sweep) was recorded for the GOx–glucose interaction, with a limit of detection of 560 μM and a regression coefficient (R2) of 0.9743 [y = 0.9106x − 0.9953] on the linear curve. The sensitivity was estimated to be 3.5 mAcm−2M−1. Furthermore, control experiments with galactose, sucrose, and fructose did not yield an increase in current‐potential, confirming specific glucose detection. This experiment helps in monitoring glucose levels to manage conditions associated with GD. [ABSTRACT FROM AUTHOR]

Sustainable functionalization of bacterial cellulose for cost‐effective bionanocomposites with desired properties has received growing attention in recent years. This article presents the results of work aimed at obtaining bionanocomposite materials based on bacterial cellulose, a natural and eco‐friendly material. Bacterial cellulose obtained from the Kombucha symbiotic culture of bacteria and yeast (SCOBY) fermentation process is functionalized by embedding with diatom frustules, silver nanoparticles (AgNPs), and poly(3,4‐ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS). The effects of functionalization on mechanical, optical, plasmonic, electrical, chemiluminescent, and antimicrobial properties are evaluated. Morphological characteristics of the nanocomposites are studied using electron microscopy. Addition of diatom frustules introduced into the SCOBY culture media results in bionanocomposite materials with enhanced tensile strength and increased ultraviolet (UV) blockage properties. In situ functionalization of bacterial cellulose with AgNPs tunes plasmonic and chemiluminescent properties, revealing the biosensing potential of the material. Modified bacterial cellulose shows antimicrobial activity in experiments with gram‐positive and gram‐negative bacteria. Dual functionalization of bacterial cellulose with PEDOT:PSS and AgNPs results in improved electrical conductivity of the bionanocomposite. Overall, bottom‐up physical functionalization approaches and the resulting bionanocomposite materials will open up new opportunities for the low‐cost production of green materials and contribute to the development of a sustainable economy. [ABSTRACT FROM AUTHOR]

Summary: This study introduces a novel sensor for glucose measurement based on a rectangular dielectric resonator (RDR) excited by a rectangular slot fed by a 50‐Ω microstrip line. The RDR operates at 6 GHz and incorporates a cubic portion section for accommodating a finger or container containing the test sample. By utilizing the distinctive resonant frequencies associated with varying dielectric permittivity of different glucose concentrations, the proposed RDR functions as a reliable sensor. The sensor's performance is evaluated through a 3D electromagnetic model of the human thumb and the application of the Cole‐Cole method for modeling the blood layer. Experimental validation is conducted using three alternatives (water, glucose, and alcohol) and a range of glucose concentrations (70 to 2000 mg/dL) in simulation. During experimental verification, an invasive glucometer is employed as a reference for blood sugar levels. Results demonstrate that the proposed RDR sensor exhibits higher sensitivity (36.86 MHz/(mg/dL)) than other sensor counterparts. The experimental outcomes confirm the resonance frequency alignment between the manufactured sensor and the simulated projections. Considering its economic viability and applicability, this sensor represents a promising alternative biosensor for monitoring blood glucose levels. [ABSTRACT FROM AUTHOR]

In India, where millions of people use groundwater for drinking, arsenic pollution in groundwater is a major environmental and public health issue. The review begins by analyzing the sources and causes of groundwater arsenic pollution, including natural geological processes and anthropogenic activities like mining and industrial discharge. It emphasizes India's most arsenic‐contaminated regions and the health risks of long‐term exposure. The review's second section focuses on the use of biosensors to find arsenic in groundwater. A potential method is provided by biosensors because of their great sensitivity, selectivity, and quick response. The benefits and drawbacks of several types of biosensors, including optical, electrochemical, and microbiological biosensors, are discussed. The utilization of nanomaterials, biomolecular recognition components, and miniature devices are only a few of the most recent developments in biosensor technology for arsenic detection that are studied. The review's last section discusses methods for bio‐remediating aqueous systems that have been contaminated with arsenic. Various bioremediation techniques are covered in detail, including microbial degradation, phytoremediation, and biosorption. The promise for removing arsenic using native microbes and plant species is highlighted, along with the difficulties of widespread application and long‐term sustainability. Overall, focusing on the detection of arsenic using biosensors and investigating bioremediation techniques, this review offers a thorough grasp of the arsenic poisoning in groundwater in India. In order to combat arsenic contamination and protect the health and wellbeing of the impacted populations in India, it emphasizes the need for interdisciplinary research and collaboration among scientists, engineers, policymakers, and local communities. [ABSTRACT FROM AUTHOR]

Pseudomonas aeruginosa is a pathogen that infects wounds and burns and causes severe infections in immunocompromised humans. The high virulence, the rise of antibiotic‐resistant strains, and the easy transmissibility of P. aeruginosa necessitate its fast detection and control. The gold standard for detecting P. aeruginosa, the plate culture method, though reliable, takes several days to complete. Therefore, developing accurate, rapid, and easy‐to‐use diagnostic tools for P. aeruginosa is highly desirable. Nanomaterial‐based biosensors are at the forefront of detecting P. aeruginosa and its secondary metabolites. This review summarises the biorecognition elements, biomarkers, immobilisation strategies, and current state‐of‐the‐art biosensors for P. aeruginosa. The review highlights the underlying principles of bioreceptor layer engineering and the design of optical, electrochemical, mass‐based, and thermal biosensors based on nanomaterials. The advantages and disadvantages of these biosensors and their future point‐of‐care applications are also discussed. This review outlines significant advancements in biosensors and sensors for detecting P. aeruginosa and its metabolites. Research efforts have identified biorecognition elements specific and selective towards P. aeruginosa. The stability, ease of preparation, cost‐effectiveness, and integration of these biorecognition elements onto transducers are pivotal for their application in biosensors and sensors. At the same time, when developing sensors for clinically significant analytes such as P. aeruginosa, virulence factors need to be addressed, such as the sensor‘s sensitivity, reliability, and response time in samples obtained from patients. The point‐of‐care applicability of the developed sensor may be an added advantage since it enables onsite determination. In this context, optical methods developed for P. aeruginosa offer promising potential. [ABSTRACT FROM AUTHOR]

Recently, field‐effect transistors (FETs) have emerged as a novel type of multiparameter, high‐performance, highly integrated platform for biochemical detection, leveraging their classical three‐terminal structure, working principles, and fabrication methods. Notably, graphene materials, known for their exceptional electrical and optical properties as well as biocompatibility, serve as a fundamental component of these devices, further enhancing their advantages in biological detection. This review places special emphasis on recent advancements in graphene field‐effect transistor (GFET)‐based biosensors and focuses on four main areas: i) the basic concepts of FETs and the specific electrical properties of GFETs; ii) various state‐of‐the‐art approaches to enhance the performance of GFET‐based biosensors in terms of operating principles and the “3S”—stability, sensitivity, and specificity; iii) multiplexed detection strategies for GFET‐based biosensors; and iv) the current challenges and future perspectives in the field of GFET‐based biosensors. It is hoped that this article can profoundly elucidate the development of GFET biosensors and inspire a broader audience. [ABSTRACT FROM AUTHOR]

The convergence of advanced nanotechnology with disease diagnosis has ushered in a transformative era in healthcare, empowering early and accurate detection of diseases and paving the way for timely interventions, improved treatment outcomes, and enhanced patient well‐being. The development of novel materials is frequently the impetus behind significant advancements in sensor technology. Among them, single‐walled carbon nanotubes (SWCNTSs) have emerged as promising nanomaterials for developing biosensors. Their unique optical, electrical, and biocompatibility properties make them promising candidates for enhancing the sensitivity and real‐time monitoring capabilities of biosensors, as well as for enabling various bioimaging techniques. Recent studies have demonstrated the utility of SWCNTS‐based biosensors in the real‐time monitoring of biological analytes, such as nitric oxide and hydrogen peroxide (H2O2), with potential implications for disease understanding and therapeutic response assessment. Moreover, SWCNTSs have shown promise in bioimaging applications, including fluorescence, Raman spectroscopy, and photoluminescence imaging of biological samples. This article delves into the core principles, design strategies, and operational mechanisms that underpin SWCNTS‐bioimaging techniques‐based biosensors. It emphasizes on their unique properties and versatile functionalization of carbon nanotubes, laying the foundation for their integration into biosensor platforms and applications aimed at diagnosing a wide spectrum of diseases including infectious diseases, cancer, neurological disorders, and metabolic conditions. [ABSTRACT FROM AUTHOR]

This work aimed to manufacture bioplastics with mechanical and electrical properties for monitoring the Rhizopus stolonifer growth in tomato fruit packaging. Bioplastics were based on chitosan/polyvinyl alcohol (Ch/PVA), chitosan/polyvinyl pyrrolidone (Ch/PVP), and nanoparticles (NPs) of plant extracts at 10% and 30% of concentrations. Bioplastics were exposed to tomato inoculated with R. stolonifer for 6 d at 25°C. Water vapor permeability (WVP), mechanical properties, FTIR, UV–vis, morphology, electrical resistance of bioplastics, and the NPs size were assessed. In bioplastics added with plant extracts, 1.5 times more WVP than in the control group (18–35 gs−1m−1Pa−1) were quantified. Ch/PVA bioplastic showed 51% more tensile strength, 44% more elongation at break, and 40% more Young's modulus than Ch/PVP, regardless of the plant extract. The electrical resistance in Ch/PVA bioplastics with 30% mushroom extract and 10% radish allowed the differentiation between inoculated (109–1010 Ω) and non‐inoculated tomatoes (1010–1011 Ω). The FTIR assay confirmed the presence of each compound used in the bioplastic, and UV–vis confirmed phenols at 300 nm. The NPs measured less than 50 nm. Only Ch/PVA with 30% mushroom and 10% radish can be useful to monitor fungi in tomatoes based on their electrical behavior. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) have emerged as promising materials for biosensing and biomedical applications due to their exceptional structural properties and tunable functionalities. Integrating functional DNA with MOFs offers numerous advantages, including enhanced colloidal stability, target‐induced signal amplification, improved cellular uptake, and controlled drug release. This focused review aims to highlight key insights into the DNA–MOF interface to facilitate the design and application of these conjugates. A succinct summary of the interactions between DNA and MOFs, covering both noncovalent adsorption and covalent conjugation is provided. Moreover, recent advancements in utilizing DNA–MOF conjugates in biosensors, with a specific emphasis on fluorescent and electrochemical sensing are discussed. Additionally, applications in bioimaging, controlled drug delivery, and nucleic acid delivery are explored. Finally, the limitations of existing designs and provide insightful perspectives for the future development of DNA–MOFs, aiming to expedite their integration and impact in the realm of biomedical applications are addressed. [ABSTRACT FROM AUTHOR]

An enzymatic fluorescent probe is developed for the selective detection of glucose. In this work, a Bovine Serum Albumin stabilized gold nanocluster (BSA‐AuNCs) was synthesized by microwave assisted method, and it is modified with glucose oxidase, thereby a fluorescent enzymatic sensor (BSA‐AuNCs@GoX) was designed for the sensitive detection of glucose with a limit of detection of 0.03 mM. The red fluorescence exhibited by the probe is quenched by the production of H2O2 on addition of glucose via. a static quenching mechanism from UV visible absorption and Fluorescence lifetime results. The developed probe exhibits good selectivity and sensitivity with other coexisting molecular species such as glycine, creatinine, methionine, histidine, uric acid, albumin, and ions such as sodium, potassium, calcium, magnesium, zinc etc. that appear in the body fluid. The practical applicability was studied in paper strip and extended its reproducibility in biological matrixes such as human serum and urine and found a good recovery percentage of 94–101 %. By this way, we have fabricated an effective fluorescent enzymatic "turn‐off" sensing probe for the detection of glucose. [ABSTRACT FROM AUTHOR]

The second‐most common cause of death resulting from genetic mutations in DNA sequences is cancer. The difficulty in the field of anticancer research is the application of the traditional methods, which also affects normal cells. Mutations, genetic replication alterations, and chromosomal abnormalities have a direct impact on the effectiveness of anticancer drugs at different stages. Presently, therapeutic techniques utilize nanotechnology, transition metal dichalcogenides (TMDCs), and robotics. TMDCs are being increasingly employed in tumor therapy and biosensing applications due to their biocompatibility, adjustable bandgap, versatile functionality, exceptional photoelectric properties, and wide range of applications. This study reports the advancement of nanoplatforms based on TMDCs that are specifically engineered for responsive and intelligent cancer therapy. This article offers a thorough examination of the current challenges, future possibilities for theranostic applications using TMDCs, and recent progress in employing TMDCs for cancer therapy. Currently, there is significant interest in two‐dimensional (2D) TMDCs nanomaterials as ultrathin unique physicochemical properties. These materials have attracted attention in various fields, including biomedicine. Due to their inherent ability to absorb near‐infrared light and their exceptionally large surface area, significant efforts are being made to prepare multifunctional nanoplatforms based on 2D TMDCs. [ABSTRACT FROM AUTHOR]

Osteoporosis is with porous bones, which refers to a decrease in the bone mineral density and weakens the bones to become brittle. Osteoporosis often progresses without any pain or symptoms until the bone fractures. Monitoring the condition of bone regularly helps to identify the bone that weakens at its earlier stages. In general, radiological techniques have been used to measure bone mineral density, are expensive, and the procedures are complicated. Therefore, researchers are focusing on the alternative method of biomarker quantification to identify bone mineral density. This research work was focused on quantifying the osteoporosis biomarker of C‐terminal telopeptide of type I collagen (CTX‐I) on an interdigitated electrode (IDE) sensor. Gold nanomaterial‐modified anti‐CTX‐I antibody was attached to silica nanomaterial‐decorated IDE and then identified by CTX‐I interaction. Higher immobilization of antibodies was recorded on diamond‐modified IDE through gold nanoparticles, and detected CTX‐I as low as 0.5 pg/mL [y = 1.5507x − 0.9043 R2 = 0.9715], determined on a linear curve at the range 0.5–3.5 ng/mL. Further, specific identification of CTX‐I was confirmed by control performances with osteopontin, IL‐6, and anti‐IgG antibody. [ABSTRACT FROM AUTHOR]

Biosensor which is used in wide range of research areas is a type of device which analyzes chemical and biological reactions by responding with electrical output. In this process graphene has become a "miracle material" due to its chemical and physical properties and it is synthesized in this process by native graphite powder (Black Lead) with slight moderation of Hummers method. For membrane formation, PVB (polyvinyle butryl) is used. This copolymer is totally amorphous in nature. An additional, most important eminence of polymer based composite materials is that they can modify chemically to enhance their elasticity biocompatibility and reactivity. The novel nanocomposite membrane can be used for photocatalytic materials for organic pollutant degradation. This experimental study is focused on synthesis and catalytic activity of electrochemical biosensing polymer nanocomposites. In fact, there are many other fields where graphene‐enhanced sensors are on the rise, such as microelectromechanical systems (MEMS) sensors, pressure sensors, pH sensors, environmental contamination sensors, gas sensors, DNA sensors, and more. [ABSTRACT FROM AUTHOR]

Among the methods for onsite detection of specific biomolecules, the use of retroreflective Janus particles (RJPs) is a simple and efficient method for biophotonic probes to detect biotarget molecules with spatioselectivity, which can make the RJPs align toward light sources after capturing the target biomolecules, enhancing retroreflection. Because RJP has two distinct regions with different properties, specific reagents can be easily functionalized through chemical reactions between the functional groups and biotarget molecules. The number of functional groups on RJP will be the critical parameter for efficiency of sensing ability. Here, clickable (azide) polymer brush is introduced on surface of RJP via different surface polymerization methods (grafting to and grafting from method). Azide groups allow for the easy modification of dibenzocyclooctyne‐linked biomolecules onto silica particles through click chemistry. RJPs are prepared with different quantities of azide functional groups on their surfaces via solvent volatilization method and metal deposition. Using a retroreflective immunosensing system, sensitive detection of target biomolecules is performed. [ABSTRACT FROM AUTHOR]

Intelligent electrospun pH indicators were produced from bio‐nanocomposite kafirin‐polyethylene oxide (PEO) containing red beetroot extract. The aim was to evaluate the performance and stability of the electrospun pH indicators via image processing. Red beetroot extract was added to a mixture of kafirin and PEO at various concentrations. The mixtures were electrospun, and infrared Fourier transform spectroscopy confirmed the presence of kafirin, PEO, and red beetroot extract in the resulting pH indicator. The results showed that the pH indicators had high stability and reversibility at different temperatures, pHs, and environmental conditions. The results showed that the color of the indicators was significantly reversible after pH changes, with highly desirable reversibility observed at pH values of 1, 3, 4, 5, 7, 9, and 10. The findings proved that the red beetroot extract loaded bio‐nanocomposite pH indicator accompanied by evaluation of color characteristics through image processing technique, can serve as a time‐efficient, accurate tool for detecting and tracking pH changes caused by food spoilage. [ABSTRACT FROM AUTHOR]

Metal nanoparticle (NP)‐catalyzed electron transfer (ET) from a reducing agent to a metal complex is useful for signal amplification in biosensors. For efficient ET, the metal complex must undergo rapid outer‐sphere reactions, be highly water‐soluble, and effectively penetrate bio/organic layers on metal NPs. Our study identifies Ru(NH3)63+ as well‐suited for this purpose. Among reducing agents, ammonia‐borane (AB) enables rapid metal NP‐catalyzed ET, with Au, Pt, and Pd NPs displaying similar catalytic activities. The pseudo second‐order rate constant for 20‐nm Au NP‐catalyzed ET from AB to Ru(NH3)63+ (1.4 × 108 M−1 s−1) approaches the diffusion‐controlled rate constant. Despite immunoglobulin G and bovine serum albumin passively adsorbed on Au NPs, catalytic activity remains largely unaffected. Applying Au NP‐catalyzed ET to prostate‐specific antigen detection in human serum achieves a low detection limit of 10 pg/mL. These findings highlight the potential of Ru(NH3)63+ and AB in designing biosensors based on rapid catalytic reaction. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) are actively explored as sensing materials owing to their high porosity, substantial surface area, and structural diversity, providing diverse chemical and physical properties. Their fluorescent characteristics are pivotal, enabling MOFs to function as probes for detecting specific target molecules. Unlike conventional disease diagnosis methods such as biopsies or blood collection, the detection of pathogenic biomarkers in human urine is conventional and less risky. While mass spectroscopy identifies proteins and metabolites in urine at high costs, MOF test papers offer a convenient solution. These papers confirm the existence of the target molecules through naked‐eye observation upon UV light irradiation at specific wavelengths. MOF‐based fluorescent probes facilitate disease diagnosis, including pheochromocytoma, toluene exposure, vitamin deficiencies, gout, hyperuricemia, cancers, body disorders, and teratogenicity, with low detection limits. This review delves into recent developments in MOF fluorescent probes, covering synthesis, emission spectra, and sensing mechanisms. [ABSTRACT FROM AUTHOR]

"Giving the cells exactly what they need, when they need it" is the core idea behind the proposed bioprocess control strategy: operating bioprocess based on the physiological behavior of the microbial population rather than exclusive monitoring of environmental parameters. We are envisioning to achieve this through the use of genetically encoded biosensors combined with online flow cytometry (FCM) to obtain a time‐dependent "physiological fingerprint" of the population. We developed a biosensor based on the glnA promoter (glnAp) and applied it for monitoring the nitrogen‐related nutritional state of Escherichia coli. The functionality of the biosensor was demonstrated through multiple cultivation runs performed at various scales—from microplate to 20 L bioreactor. We also developed a fully automated bioreactor—FCM interface for on‐line monitoring of the microbial population. Finally, we validated the proposed strategy by performing a fed‐batch experiment where the biosensor signal is used as the actuator for a nitrogen feeding feedback control. This new generation of process control, —based on the specific needs of the cells, —opens the possibility of improving process development on a short timescale and therewith, the robustness and performance of fermentation processes. [ABSTRACT FROM AUTHOR]

Outbreaks of infectious viruses offer a formidable challenge to public healthcare systems and early detection of viruses is essential for preventing virus propagation. In this work, an ultrasensitive plasmon‐enhanced fluorescence resonance energy transfer (FRET) biosensor based on core‐shell upconversion nanoparticle (csUCNP) and gold nanoparticle (AuNP) for accurate detection of SARS‐CoV‐2 viral RNA is presented. In this biodetection assay, the Tm3+/Er3+ co‐doped csUCNP NaGdF4:Yb/Tm@NaYF4:Yb/Er acts as an energy donor and AuNP serves as an energy acceptor. The upconversion emission of Tm3+ and the design of the core‐shell structure led to a simultaneous surface plasmon effect of AuNP. The localized surface plasmon resonance (LSPR) arising from collective oscillations of free electrons significantly enhanced FRET efficiency between Er3+ and AuNP. The as‐prepared biosensor obtained a limit of detection (LOD) as low as 750 am, indicating that the integration of FRET and surface plasmon into one biodetection assay significantly boosted the sensitivity of the biosensor. In addition, samples extracted from clinical samples are also utilized to validate the effectiveness of the biosensor. Therefore, this innovative plasmon‐enhanced FRET biosensor based on Tm3+/Er3+ co‐doped csUCNP may pave the way for rapid and accurate biodetection applications. [ABSTRACT FROM AUTHOR]

The injectable hydrogels can deliver the loads directly to the predetermined sites and form reservoirs to increase the enrichment and retention of the loads in the target areas. The preparation and injection of injectable hydrogels involve the sol–gel transformation of hydrogels, which is affected by factors such as temperature, ions, enzymes, light, mechanics (self‐healing property), and pH. However, tracing the injection, degradation, and drug release from hydrogels based on different ways of gelation is a major concern. To solve this problem, contrast agents are introduced into injectable hydrogels, enabling the hydrogels to be imaged under techniques such as fluorescence imaging, photoacoustic imaging, magnetic resonance imaging, and radionuclide imaging. This review details methods for causing the gelation of imageable hydrogels; discusses the application of injectable hydrogels containing contrast agents in various imaging techniques, and finally explores the potential and challenges of imageable hydrogels based on different modes of gelation. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: N6‐methyladenosine (m6A) plays an important role in embryogenesis, nuclear export, transcription splicing, and protein translation control. Herein, we demonstrate a copper‐free click chemistry‐mediated assembly of single quantum dot (QD) nanosensor for accurately monitoring locus‐specific m6A in cancer cells. The m6A‐sensitive endoribonuclease MazF can digest the unmethylated A‐RNA, and the intact m6A‐RNA then hybridizes with DNA probes a and b to produce a sandwich hybrid, initiating the click chemistry to generate probe a–b ligation product via first tandem ligation detection reaction (LDR) cycle. Subsequently, DNA probes c and d can hybridize with the probe a–b ligation product to generate the probe c–d ligation product via second LDR cycle. Both LDR cycles can be repeated through denaturation and annealing reaction to generate abundant biotin‐/fluorophore‐modified probe c–d ligation products that can easily assemble on the QD surface to induce distinct fluorescence resonance energy transfer (FRET) between QD and Cy5. This assay can be homogenously performed without the involvement of copper catalyst, m6A‐specific antibody, radioactive labeling, ligase enzyme, enzymatic reverse transcription, and next‐generation sequencing. Moreover, it can discriminate even 0.01% m6A level in complex samples and accurately measure cellular m6A‐RNA expression, providing a promising avenue for clinical diagnostics and biomedical research. [ABSTRACT FROM AUTHOR]

The simultaneous detection of multiple analytes using electrochemical biosensor arrays has demonstrated significant potential in various fields, including medical diagnostics. These platforms are designed to be low‐cost, easy to use, and offer fast detection of a range of molecules. This concept article discusses the components necessary to achieve multiplexing with electrochemical biosensor arrays. The various methods used to fabricate electrode arrays of different types are discussed. Furthermore, the methods for the selective immobilization of multiple different bioreceptors onto individual electrodes within the array, a crucial step essential for conferring specificity to the analytical processes, are presented with relevant examples. We have focused on enzymes, antibodies and aptamers as examples of bioreceptors that have been deployed in various multianalyte electrochemical detection platforms. Finally, we discuss the key challenges associated with their application for the analysis of real samples and provide a future outlook on possible strategies that can be used to overcome these challenges. [ABSTRACT FROM AUTHOR]

This study presents a new dual‐metal dopingless tunnel field effect transistor with a Germanium source (GeS‐DM‐DLT) for label‐free biomolecule detection. Introducing a Ge source and dual‐metal gate provides improved drain current. We have considered an L‐shaped cavity at the top and bottom source metal region for investigating the sensitivity. The biosensor's sensitivity has been measured using the neutral biomolecules' dielectric constants (varying the k‐values in the cavity). The sensor's DC performance is investigated using transfer characteristics, BTBT rate, energy band, and electric field variation for different k‐values. The sensitivity performance of the proposed biosensor is evaluated in terms of different DC parameters (drain current, surface potential, subthreshold swing, interband tunneling rate, electric field) and RF parameters (parasitic capacitance, transconductance, cut‐off frequency, maximum frequency). The suggested biosensor offers a much‐improved SON of 9.86 × 108 and SRATIO of 1.94 × 104 for a dielectric constant of 22.0 at room temperature. Further research has been done to study the effects of dielectric materials, interface trap carriers (ITC), and temperature on drain current, drain current sensitivity, and other sensitivity parameters. The article also includes investigating the influence of the fill factor on sensitivity performance. The GeS‐DM‐DLT sensor performs best in fully‐filled conditions compared to the partially‐filled condition inside the cavity region. [ABSTRACT FROM AUTHOR]

In the present paper, a biosensor is proposed with a split gate dielectric modulated bottom gate top contact organic thin‐film transistor. A cavity is marked below gate metal for enhancing sensitivity in biomedical applications. The organic thin‐film transistors‐based biosensors have shown applications over advanced biosensing platforms due to their intrinsic ability to transfer and amplify received biological signals into respective electrical signals. Immobilizing the biomolecules inside the cavity generates changes in surface potential. The analysis is carried out via different performance metrics that directly affect device electrical characteristics such as a change in spacer length applied voltages (Vgs and Vds) as well as channel material. After modeling, the device output characteristics are compared corresponding to simulated outcomes that validated our results. The proposed model structure is categorized by dividing it into different sections. Each categorized section's surface potential is further evaluated via 1‐ and 2‐dimensional Poisson's equation. The simulations to recreate biomolecules in terms of dielectric constant and charge density are done in the Silvaco ATLAS tool. The maximum value of sensitivity of proposed biosensor is around 300 in the case of charged biomolecule detection. [ABSTRACT FROM AUTHOR]

Hepatitis C remains a global health problem, especially in poverty‐stricken areas. A rapid and sensitive point‐of‐care (POC) diagnostic tool is critical for the early detection and timely treatment of hepatitis C virus (HCV) infection. Here, for the first time, we reported a novel molecular diagnostic assay, termed reverse transcription multiple cross displacement amplification integrated with a gold‐nanoparticle‐based lateral flow biosensor (RT‐MCDA‐AuNPs‐LFB), which was developed for rapid, sensitive, specific, and visual identification of HCV. HCV‐RT‐MCDA induced rapid isothermal amplification through a specific primer set targeting the 5′untranslated region gene from the major HCV genotypes 1b, 2a, 3b, 6a, and 3a that are prevalent in China. The optimal reaction temperature and time for RT‐MCDA‐AuNPs‐LFB were 68°C and 25 min, respectively. The limit of detection of the assay was 10 copies per test, and the specificity was 100% for the experimental strains. The whole detection procedure, including crude nucleic acid isolation (~5 min), RT‐MCDA (68°C, 25 min), and visual AuNPs‐LFB result confirmation (less than 2 min), was performed within 35 min. The preliminary results indicated that the HCV‐RT‐MCDA‐AuNPs‐LFB assay could be a valuable tool for sensitive, specific, visual, cost‐saving, and rapid detection of HCV and has potential as a POC diagnostic platform for field screening and early clinical detection of HCV infection. [ABSTRACT FROM AUTHOR]

In this study, we present a novel functionalized single‐walled carbon nanotubes (SWCNTs) electrochemical aptasensor designed for the detection of HER2 breast cancer. The well‐organized SWCNTs were attained through a concentration‐based and single‐step ultrasonication‐directed assembly methodology, resulting in a well‐dispersed state and a thin, even coating on the transducer substrate. Well‐organized SWCNTs were systematically analyzed through X‐ray diffraction spectroscopy (XRD), Fourier transforms infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy and elemental mapping (TEM‐mapping) and X‐ray photoelectron spectroscopy (XPS) confirmed the superior quality and organization of the SWCNTs. Furthermore, the electrochemical sensor exhibited outstanding performance, showcasing the potential of the SWCNTs as an ideal material for such applications, including their anticancer activity against human breast cancer cells. The single‐step ultrasonication‐directed assembly approach not only enhances the electrochemical properties of SWCNT but holds promise as a potentially as versatile substrate for immobilizing enzymes, antibodies, and DNA. This versatility opens up opportunities for the creation of highly functional biosensors with broad medical applications. Overall, our findings highlight the scientific significance of SWCNTs in advancing electrochemical sensing technologies and their potential in combating breast cancer. [ABSTRACT FROM AUTHOR]

Biosensors to measure protein stability in vivo are valuable tools for a variety of applications. Previous work has demonstrated that a tripartite design, whereby a protein of interest (POI) is inserted within a reporter, can link POI stability to reporter activity. Inteins are translated within other proteins and excised in a self‐mediated protein splicing reaction. Here, we developed a novel folding biosensor where a POI is inserted within an intein, which is subsequently translated within an antibiotic resistance marker. We showed that protein splicing is required for antibiotic resistance and that housing a stable POI within the intein, compared to an unstable variant, results in a 100,000‐fold difference in survival. Further, using a fluorescent protein that matures slowly as the POI, we developed a reporter with two simultaneous readouts for protein folding. Finally, we showed that co‐expression of GroEL can significantly increase the activity of both reporters, further verifying that protein folding factors can act on the POI in the biosensor. As a whole, our work provides a new twist on the traditional tripartite approach to measuring protein stability in vivo. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: N6‐methyladenosine (m6A) plays an important role in embryogenesis, nuclear export, transcription splicing, and protein translation control. Herein, we demonstrate a copper‐free click chemistry‐mediated assembly of single quantum dot (QD) nanosensor for accurately monitoring locus‐specific m6A in cancer cells. The m6A‐sensitive endoribonuclease MazF can digest the unmethylated A‐RNA, and the intact m6A‐RNA then hybridizes with DNA probes a and b to produce a sandwich hybrid, initiating the click chemistry to generate probe a–b ligation product via first tandem ligation detection reaction (LDR) cycle. Subsequently, DNA probes c and d can hybridize with the probe a–b ligation product to generate the probe c–d ligation product via second LDR cycle. Both LDR cycles can be repeated through denaturation and annealing reaction to generate abundant biotin‐/fluorophore‐modified probe c–d ligation products that can easily assemble on the QD surface to induce distinct fluorescence resonance energy transfer (FRET) between QD and Cy5. This assay can be homogenously performed without the involvement of copper catalyst, m6A‐specific antibody, radioactive labeling, ligase enzyme, enzymatic reverse transcription, and next‐generation sequencing. Moreover, it can discriminate even 0.01% m6A level in complex samples and accurately measure cellular m6A‐RNA expression, providing a promising avenue for clinical diagnostics and biomedical research. [ABSTRACT FROM AUTHOR]

Cyanide is a highly poisonous and hazardous substance which may release into the environment from natural sources or industrial effluent; therefore, cyanide detection is a fundamental step to prevent environmental pollution and secure health and safety. In this study, we prepared a sensitive amperometric inhibition biosensor for cyanide detection by immobilization of horseradish peroxidase (HRP) enzyme and reduced graphene oxide (rGO) on the surface of glassy carbon electrode (GCE). To do so, we performed the amperometric measurement by modified GCE to test its efficiency in detecting cyanide. The optimum conditions of pH equal to 7.5, −100 mV applied potential, 0.7 μM mediator concentration, and 0.5 mM substrate concentration were found. Then, experiments were performed at different boundary conditions in a range of 0.1 to 10 μM cyanide concentration at optimal conditions and a low detection limit of 0.01 μM was obtained. Also, the possible mechanism of inhibition was analyzed based on the Michalis–Menten equation and non‐competitive inhibition was observed. Due to high sensitivity, low detection limit, and low cost, this biosensor is proposed as a useful method for cyanide determination in real samples. [ABSTRACT FROM AUTHOR]

Transition metal dichalcogenides (TMDCs) are versatile two‐dimensional (2D) nanomaterials used in biosensing applications due to their excellent physical and chemical properties. Due to biomaterial target properties, biosensors' most significant challenge is improving their sensitivity and stability. In environmental analysis, TMDCs have demonstrated exceptional pollutant detection and removal capabilities. Their high surface area, tunable electronic properties, and chemical reactivity make them ideal for sensors and adsorbents targeting various contaminants, including heavy metals, organic pollutants, and emerging contaminants. Furthermore, their unique electronic and optical properties enable sensitive detection techniques, enhancing our ability to monitor and mitigate environmental pollution. In the food analysis, TMDCs‐based nanomaterials have shown remarkable potential in ensuring food safety and quality. These nanomaterials exhibit high specificity and sensitivity for detecting contaminants, pathogens, and adulterants in various food matrices. Their integration into sensor platforms enables rapid and on‐site analysis, reducing the reliance on centralized laboratories and facilitating timely interventions in the food supply chain. In biomedical studies, TMDCs‐based nanomaterials have demonstrated significant strides in diagnostic and therapeutic applications. Their biocompatibility, surface functionalization versatility, and photothermal properties have paved the way for novel disease detection, drug delivery, and targeted therapy approaches. Moreover, TMDCs‐based nanomaterials have shown promise in imaging modalities, providing enhanced contrast and resolution for various medical imaging techniques. This article provides a comprehensive overview of 2D TMDCs‐based biosensors, emphasizing the growing demand for advanced sensing technologies in environmental, food, and biomedical analysis. [ABSTRACT FROM AUTHOR]

Genetically encoded, fluorescent protein (FP)‐based Förster resonance energy transfer (FRET) biosensors are microscopy imaging tools tailored for the precise monitoring and detection of molecular dynamics within subcellular microenvironments. They are characterised by their ability to provide an outstanding combination of spatial and temporal resolutions in live‐cell microscopy. In this review, we begin by tracing back on the historical development of genetically encoded FP labelling for detection in live cells, which lead us to the development of early biosensors and finally to the engineering of single‐chain FRET‐based biosensors that have become the state‐of‐the‐art today. Ultimately, this review delves into the fundamental principles of FRET and the design strategies underpinning FRET‐based biosensors, discusses their diverse applications and addresses the distinct challenges associated with their implementation. We place particular emphasis on single‐chain FRET biosensors for the Rho family of guanosine triphosphate hydrolases (GTPases), pointing to their historical role in driving our understanding of the molecular dynamics of this important class of signalling proteins and revealing the intricate relationships and regulatory mechanisms that comprise Rho GTPase biology in living cells. [ABSTRACT FROM AUTHOR]

Cholesterol is an essential lipid molecule associated with various physiological and pathological processes in the human body. Elevated cholesterol levels are correlated with several diseases, such as atherosclerosis, making cholesterol a critical biomarker for health monitoring. Molecular imprinting technology was selected to fabricate cholesterol imprinted microsphere (CHOL‐IP). This approach creates tailor‐made binding sites within polymer matrices for capturing cholesterol. However, the limited functional group in steroid derivative pose a challenge for the imprinting strategy. In this study, we successfully synthesized CHOL‐IP using a metal chelating monomer, N,N′‐vinylbenzyl iminodiacetic acid (VBIDA), in conjunction with copper (II) ions. The metal coordination approach facilitated strong binding forces, resulting in improved stability and specificity of the molecularly imprinted polymer (MIP). The synthesized CHOL‐IP was tested with pooled human serum samples containing cholesterol, HDL, and LDL. The CHOL‐IP exhibited significantly higher binding efficiency towards these compounds compared to the control polymer (CP). The application of a metal‐chelating functional monomer in the synthesized CHOL‐IP revealed the potential for enhancing its strong binding property toward cholesterol. This suggests that CHOL‐IP could be employed in the development of a cholesterol‐imprinted biosensor, providing an alternative tool for cholesterol analysis in medical detection applications. [ABSTRACT FROM AUTHOR]

Lanthanides have unique electronic configurations and stepped energy states of [Xe]4fN, which endows them with advantages including stable luminescence, large stokes shift, wide excitation spectral bands, and long fluorescence lifetime. NIR‐II fluorescence imaging overcomes the strong tissue absorption, scattering, and spontaneous fluorescence interference of traditional fluorescence and can achieve deeper tissue penetration and higher spatial and temporal resolution in vivo imaging. Lanthanides hold great potential for in vivo biosensing and bioimaging. In this work, the design and preparation of nanomaterials doped with different lanthanide elements are reviewed in this paper. Applications of lanthanide‐doped nanomaterials to different tumor therapeutics through NIR‐II fluorescence imaging and the unique potential of NIR lanthanide nanomaterials in tumor diagnosis and therapy are also discussed. [ABSTRACT FROM AUTHOR]