Development Of Biosensors Research Articles

Maleylpyruvic Acid-Inducible Gene Expression System and Its Application for the Development of Gentisic Acid Biosensors.

Gentisic acid is a secondary plant metabolite, known for its health benefits, not only widely used as a supplement but also implicated as a potential biomarker for cancer-associated metabolism alterations. To advance bioproduction and detection of this compound or its derivatives, cell-based approaches have become of interest in recent years. However, the lack of tools for high-throughput gentisic acid monitoring and compound-metabolizing organism screening limits the progress in this area. Here, we analyzed the gene cluster responsible for gentisic acid metabolism in Cupriavidus necator H16. The transcriptional regulator GtdR-based inducible gene expression system CnGtdR/PgtdA was elucidated, showing that it was activated when C. necator cells were subjected to gentisic acid. Subsequently, a 3-maleylpyruvic acid was identified as a primary inducer for this inducible system. Furthermore, genes gtdA and gtdT, encoding for gentisate 1,2-dioxygenase and MFS transporter, were shown to be essential for inducible system activation in the presence of gentisic acid with GtdA enabling conversion of this phenolic acid into the inducer. The CnGtdRAT/PgtdA-based inducible system was employed to develop a whole-cell biosensor for the intracellular and extracellular detection of gentisic acid. The potential of the 3-maleylpyruvic acid-inducible system was demonstrated by its application in metabolic pathway research, detection of highly unstable 3-maleylpyruvic acid, and development of biosensors for the intracellular or extracellular determination of gentisic acid. In addition, the utility of the biosensor was emphasized by its application for detection of gentisic acid as a potential biomarker for cancer in urine samples.

Molecular Spies in Action: Genetically Encoded Fluorescent Biosensors Light up Cellular Signals.

Cellular function is controlled through intricate networks of signals, which lead to the myriad pathways governing cell fate. Fluorescent biosensors have enabled the study of these signaling pathways in living systems across temporal and spatial scales. Over the years there has been an explosion in the number of fluorescent biosensors, as they have become available for numerous targets, utilized across spectral space, and suited for various imaging techniques. To guide users through this extensive biosensor landscape, we discuss critical aspects of fluorescent proteins for consideration in biosensor development, smart tagging strategies, and the historical and recent biosensors of various types, grouped by target, and with a focus on the design and recent applications of these sensors in living systems.

Eggshell‐Based Unconventional Biomaterials for Medical Applications

Eggshells are one of the most abundant byproducts of food processing waste. Each discarded eggshell represents a missed opportunity to convert a no‐cost waste material into a valuable product. Beyond their economic practicality and widespread availability, eggshells possess unique biological and chemical properties that support cell differentiation. Their composition includes biologically active compounds, essential trace elements, and collagenous and noncollagenous elements, mimicking the components of bones, teeth, and skin. Additionally, eggshells serve as a suitable precursor for synthesizing hydroxyapatite, calcium carbonate (CaCO3), and β‐tricalcium phosphate. Eggshells can be utilized on their own or as derived materials to produce regenerative biocomposite scaffolds for tissue engineering. These scaffolds often exhibit high porosity, excellent biocompatibility, degradability, and mechanical properties. Eggshells and their derivatives have also been employed as carriers for targeted drug delivery systems and in electrochemical biosensors. Eggshells serve as a versatile biomaterial, adept at not only addressing practical gaps but also bridging the divide between sophistication and ease of production. In this review, the chemical composition of eggshells and their numerous applications in hard and soft tissue regeneration, biomolecule delivery, and biosensor development are discussed highlighting their innovative and unconventional use as a natural biomaterial providing solutions for unmet clinical needs.

Functional Organic Electrochemical Transistor-Based Biosensors for Biomedical Applications

Organic electrochemical transistors (OECTs), as an emerging device for the development of novel biosensors, have attracted more and more attention in recent years, demonstrating their promising prospects and commercial potential. Functional OECTs have been widely applied in the field of biosensors due to their decisive advantages, such as high transconductance, easy functionalization, and high integration capability. Therefore, this review aims to provide a comprehensive summary of the most recent advances in the application of functional OECT-based biosensors in biomedicine, especially focusing on those biosensors for the detection of physiological and biochemical parameters that are critical for the health of human beings. First, the main components and basic working principles of OECTs will be briefly introduced. In the following, the strategies and key technologies for the preparation of functional OECT-based biosensors will be outlined and discussed with regard to the applications of the detection of various targets, including metabolites, ions, neurotransmitters, electrophysiological parameters, and immunological molecules. Finally, the current main issues and future development trends of functional OECT-based biosensors will be proposed and discussed. The breakthrough in functional OECT-based biosensors is believed to enable such devices to achieve higher performance, and thus, this technology could provide new insight into the future field of medical and life sciences.

The development of carbon nanostructured biosensors for glucose detection to enhance healthcare services: a review

In this review, the forefront of biosensor development has been marked by a profound exploration of carbon nanostructured materials for the specific application of glucose detection. Moreover, this progressive line of inquiry capitalizes on the distinctive attributes of carbon nanostructured materials such as carbon nanotubes, carbon quantum dots, and graphene which exhibit unique characteristics in the development of biosensor engineering design. It also enhanced analytical performances regarding the limit of detection, selectivity, sensitivity, and reproducibility towards glucose detection in biological samples. Most importantly, the strategic integration of carbon nanostructured-based biosensor architectures has played a significant role in advancements, characterized by heightened sensitivity, exquisite selectivity, and augmented stability in glucose detection processes. Furthermore, utilizing these advanced materials has engendered a transformative impact on electrochemical properties, propelling the biosensors to achieve rapid and precise glucose-sensing capabilities. The confluence of carbon nanostructures with biosensor technology has not only elevated the scientific understanding of glucose detection mechanisms. Still, it has also paved the way for miniaturized and portable biosensors. This transformative shift holds great promise for the realization of point-of-care diagnostics, representing a pivotal step towards durability and efficient glucose monitoring in health/medical care. These advancements emphasize the crucial role of carbon nanostructured-based biosensors in opening the way to a new avenue of superiority and effectiveness in diabetes management. Conclusively, the challenges and, in a forward-looking stance, the prospective futures of glucose biosensors anchored on carbon nanostructured frameworks were considered.

Electrochemical Biosensors in Diagnostic Medicine: Detecting Lung Cancer Biomarkers – A Comprehensive Review

AbstractElectrochemical biosensors use biomolecules, such as proteins, enzymes, and antibodies, to translate the analytical signals detected in a sample. They have diverse applications including pesticide detection in agriculture, water analysis in various sectors, and biomedical and forensic diagnostics. With the estimated number of cancer cases in the US in 2024 being over two million, particularly lung cancer, which is notoriously difficult to diagnose early, the integration of biosensors into the Point‐of‐care Testing (PoCT) strategy can significantly improve the detection of cancer biomarkers, contributing to early diagnosis and successful treatment. Three‐dimensional (3D) printing is a promising alternative for reducing production costs and customizing devices in various ways. This review highlights recent trends and research on the development of electrochemical biosensors for early detection of lung cancer. These biosensors are expected to be more sensitive and selective for a variety of real samples and are precise, accurate, and stable during their commercialization. Significant progress has been made in the development of electrochemical devices for the early diagnosis of lung cancer, with various biomarker anchoring and detection strategies addressed throughout the study. Overcoming these challenges is key to advancing the use of these biosensors, thus improving diagnostic accuracy and enabling the successful treatment of lung cancer patients.

Engineering modular and tunable single-molecule sensors by decoupling sensing from signal output.

Biosensors play key roles in medical research and diagnostics. However, the development of biosensors for new biomolecular targets of interest often involves tedious optimization steps to ensure a high signal response at the analyte concentration of interest. Here we show a modular nanosensor platform that facilitates these steps by offering ways to decouple and independently tune the signal output as well as the response window. Our approach utilizes a dynamic DNA origami nanostructure to engineer a high optical signal response based on fluorescence resonance energy transfer. We demonstrate mechanisms to tune the sensor's response window, specificity and cooperativity as well as highlight the modularity of the proposed platform by extending it to different biomolecular targets including more complex sensing schemes. This versatile nanosensor platform offers a promising starting point for the rapid development of biosensors with tailored properties.

Development of a specific biosensor for sesquiterpene based on SELEX and directed evolution platforms

Biosensors are essential in synthetic biology, particularly for detecting compounds without distinct visual markers. In this study, a riboswitch biosensor specifically responsive to a sesquiterpene — amorpha-4,11-diene was developed for the first time. Through SELEX-SMB, a high-affinity aptamer library comprising 81,520 sequences was generated. Subsequent screening via the TBG-directed evolution platform identified riboswitch5, which downregulates downstream gene expression in response to amorpha-4,11-diene within a concentration range of 10–100 mg/L, achieving a log₂Foldchange of −0.51 at 100 mg/L. Structural predictions, combined with molecular docking and molecular dynamics simulations, revealed that ligand binding induced conformational changes that stabilize the riboswitch and enhance its repressive effect. This biosensor represents a powerful tool for the detection and regulation of small molecules, with broad applications in strain engineering, pathway regulation, and metabolic optimization in synthetic biology.

Development of flexible glucose biosensor for fish stress monitoring

Development of flexible glucose biosensor for fish stress monitoring

Towards the Development of an Optical Biosensor for the Detection of Human Blood for Forensic Analysis.

Blood is a common biological fluid in forensic investigations, offering significant evidential value. Currently employed presumptive blood tests often lack specificity and are sample destructive, which can compromise downstream analysis. Within this study, the development of an optical biosensor for detecting human red blood cells (RBCs) has been explored to address such limitations. Aptamer-based biosensors, termed aptasensors, offer a promising alternative due to their high specificity and affinity for target analytes. Aptamers are short, single-stranded DNA or RNA sequences that form stable three-dimensional structures, allowing them to bind to specific targets selectively. A nanoflare design has been employed within this work, consisting of a quenching gold nanoparticle (AuNP), DNA aptamer sequences, and complementary fluorophore-labelled flares operating through a fluorescence resonance energy transfer (FRET) mechanism. In the presence of RBCs, the aptamer-flare complex is disrupted, restoring fluorescence and indicating the presence of blood. Two aptamers, N1 and BB1, with a demonstrated binding affinity to RBCs, were selected for inclusion within the nanoflare. This study aimed to optimise three features of the design: aptamer conjugation to AuNPs, aptamer hybridisation to complementary flares, and flare displacement in the presence of RBCs. Fluorescence restoration was achieved with both the N1 and BB1 nanoflares, demonstrating the potential for a functional biosensor to be utilised within the forensic workflow. It is hoped that introducing such an aptasensor could enhance the forensic workflow. This aptasensor could replace current tests with a specific and sensitive reagent that can be used for real-time detection, improving the standard of forensic blood analysis.

Development and Optimization of a Redox Enzyme-Based Fluorescence Biosensor for the Identification of MsrB1 Inhibitors

MsrB1 is a thiol-dependent enzyme that reduces protein methionine-R-sulfoxide and regulates inflammatory response in macrophages. Therefore, MsrB1 could be a promising therapeutic target for the control of inflammation. To identify MsrB1 inhibitors, we construct a redox protein-based fluorescence biosensor composed of MsrB1, a circularly permutated fluorescent protein, and the thioredoxin1 in a single polypeptide chain. This protein-based biosensor, named RIYsense, efficiently measures protein methionine sulfoxide reduction by ratiometric fluorescence increase. We used it for high-throughput screening of potential MsrB1 inhibitors among 6868 compounds. A total of 192 compounds were selected based on their ability to reduce relative fluorescence intensity by more than 50% compared to the control. Then, we used molecular docking simulations of the compound on MsrB1, affinity assays, and MsrB1 activity measurement to identify compounds with reliable and strong inhibitory effects. Two compounds were selected as MsrB1 inhibitors: 4-[5-(4-ethylphenyl)-3-(4-hydroxyphenyl)-3,4-dihydropyrazol-2-yl]benzenesulfonamide and 6-chloro-10-(4-ethylphenyl)pyrimido[4,5-b]quinoline-2,4-dione. They are heterocyclic, polyaromatic compounds with a substituted phenyl moiety interacting with the MsrB1 active site, as revealed by docking simulation. These compounds were found to decrease the expression of anti-inflammatory cytokines such as IL-10 and IL-1rn, leading to auricular skin swelling and increased thickness in an ear edema model, effectively mimicking the effects observed in MsrB1 knockout mice. In summary, using a novel redox protein-based fluorescence biosensor, we identified potential MsrB1 inhibitors that can regulate the inflammatory response, particularly by influencing the expression of anti-inflammatory cytokines. These compounds are promising tools for understanding MsrB1’s role during inflammation and eventually controlling inflammation in therapeutic approaches.

A fluorescent biosensor based on surface cell imprinting film for Salmonella typhimurium detection

Salmonella typhimurium (S. typhimurium) is a major foodborne pathogen that poses a potentialrisk to public health. The development of biosensors that are specific, sensitive, and easy to manipulate can greatly reduce the potential risk posed by S. typhimurium. A robust, highly sensitive and specific fluorescent biosensor was proposed by combining N-succinyl-chitosan-doped surface bacterial cell imprinted film (SCIF) with typical aggregation induced emission (AIE) fluorescent substance Au(I)-disulfide nanoparticles. The proposed fluorescent sensor can achieve linear detection of S. typhimurium in the concentration range from 10 to 106 CFU/mL with a detection limit of 4 CFU/mL. In addition, the modification of the SCIF on the surface enables specific abiotic recognition of the target bacteria. This fluorescence sensing strategy can be used for the detection of S. typhimurium in chicken meat samples. The platform can be replicated for the detection of other bacteria or cells via making different SCIFs, which is promising for the detection of practical samples for clinical and biological applications.

Preparation and application of ZnO-Ecoflex composite sensors for lactate detection during physical training

This study presents the development of a flexible ZnO-Ecoflex composite sensor for noninvasive lactate detection during physical training. ZnO nanostructures with an average diameter of 50 nm were synthesized and incorporated into an Ecoflex matrix. The optimized sensor, featuring 15 wt% ZnO loading, demonstrated high sensitivity (22.7 μA·mM⁻¹·cm⁻²) and a low detection limit (2.3 μM). The composite displayed impressive mechanical characteristics, showcasing a tensile strength of 1.3 MPa and an elongation at fracture of 390%. Electrochemical characterization revealed a diffusion-controlled electron transfer process and rapid response time of 5 seconds. The sensor showed minimal interference from common sweat components (<3.2% relative response) and maintained consistent performance under various bending conditions (RSD 3.2%). Real-time monitoring during a 30-minute jogging session demonstrated the sensor's ability to capture dynamic changes in sweat lactate levels. This research contributes to the development of wearable biosensors for continuous lactate monitoring in sports and exercise science, offering potential for personalized training optimization.

The development of a whole-cell biosensor enabled the identification of agmatine-producing Hafnia spp. in cheese

Agmatine, the decarboxylation product of arginine, is the precursor of putrescine - a harmful biogenic amine (BA) - that can accumulate in dairy products via bacterial metabolism involving the agmatine deiminase (AGDI) pathway. This first requires agmatine be produced via the decarboxylation of arginine and it remains unknown which microorganisms are responsible for this prior decarboxylation step.In addition, agmatine, as other BA, plays different physiological roles including those of co-transmitter and neuromodulator. Preclinical and clinical studies have shown agmatine to have a neuroprotective effect, rendering it of therapeutic interest being agmatine-producing bacteria proposed as psychobiotics.The identification of BA-producing microorganisms is based on the rise in pH due to the consumption of H+ during such decarboxylation reactions. However, in the detection of agmatine-producing microorganisms in cheese, this would lead to false positives since many bacteria possess arginine deiminase activity; this produces ornithine and ammonium from arginine, which also increases the pH. To overcome this problem, a whole-cell biosensor based on a previously developed agmatine-inducible transcription system was designed, and a protocol optimized for the successful identification of agmatine-producing microorganisms in cheese.The application of this protocol in cheese samples allowed for the isolation of agmatine-producing microorganisms identified as Hafnia spp. and unravels, for first time, the capacity of Hafnia paralvei to produce agmatine. This finding evidence the potential role of Hafnia spp. in putrescine accumulation in dairy products.

Electrochemistry–glucosemeter–smartphone integrated multi-mode biosensor for accurate detection of aflatoxin B1

BackgroundAflatoxin B1 (AFB1) is a widely distributed toxic contaminant in food and poses a serious threat to public health. Therefore, an accurate, simple, cost-effective and on-site assay method is needed for sensitive detection of AFB1. Aptamer shows great potential in the construction of biosensor due to its high specificity and affinity. Multimodal biosensor based on aptamer is highly suitable for the analysis of AFB1 under complex conditions. And the detection results in different modes can be verified with each other, which greatly improves the accuracy of AFB1 detection. ResultsHerein, accurate detection of AFB1 was achieved through the development of a multi-mode biosensor integrating electrochemistry, glucosemeter and smartphone-based colorimetric quantification. Streptavidin-Cu3(PO4)2 hybrid nanoflowers (SA-Cu3(PO4)2 HNFs) were synthesised and then conjugated with biotinylated invertase as a signal probe. The electrochemical signal was achieved via intrinsic redox activity. Simultaneously, sucrose could be converted to glucose by the action of invertase, which can cause changes in the glucosemeter signal as well as in the colour of urine glucose test strips. The glucosemeter could complete the signal response in 7 s, and the urine glucose test strips could complete the colour development in 30 s. The detection range of AFB1 by this system in electrochemical mode is 0.001–100 ng/mL, and in glucosemeter mode and smartphone mode is 0.01–50 ng/mL. The limits of detection were 0.49 pg/mL in electrochemistry mode, 5.4 pg/mL in glucosemeter mode and 3.7 pg/mL in smartphone mode. SignificanceThe successful construction of this multi-mode biosensor demonstrates the advantages of multifunctional nanomaterials and mobile technology. Rapid and accurate detection of AFB1 is achieved through the integration of electrochemistry, glucosemeter and smartphone-based colorimetric quantification. And this biosensor provides a novel detection platform that combines sensitivity, accuracy, affordability and portability for rapid on-site food safety screening.

Tunable Multi-Enzyme Activities of Platinum Nanoclusters for Enhanced Specificity and Sensitivity in Biosensing

Nanozymes have gained prominence for their utility in biosensing and disease diagnostics. However, challenges arise from complex sample matrices and nonspecific enzyme activities that contribute to false signals. This study introduces multifunctional platinum nanoclusters (Pt NCs) exhibiting peroxidase-like (POD-like), oxidase-like (OXD-like), and laccase-like activities tailored for enhanced biosensing capabilities. By adjusting pH, we optimized the conditions to achieve distinct POD-like and OXD-like responses, thereby reducing background signals and improving detection accuracy. The addition of ATP further amplified the POD-like activity while minimizing interference from OXD-like activity. This combined strategy substantially enhanced biomarker detection selectivity, demonstrated through glucose detection in human serum samples. Moreover, thiol inhibition of laccase-like activity in Pt NCs was leveraged for thiol-based antioxidant assessment, revealing their application in quantifying total antioxidant capacity (TAC) in human liver cancer cells, accounting for 44% of TAC. The Pt NCs demonstrated robust sensitivity and reusability, offering a novel multi-enzyme nanomaterial with potential for precise and interference-free biosensing applications. These findings contribute to the development of advanced nanozyme-based biosensors, addressing specificity regulation challenges and expanding their practical application in biosensing and disease diagnostics.

Enhanced ePAD-DNA biosensor incorporating ZnO-NRs: Rapid and reliable electrochemical detection of field-isolated Pasteurella multocida

An electrochemical sensor has received much attention due to its importance for early infection identification, hinting at its critical relevance in diagnostic applications. For the detection of field-isolated strains of Pasteurella multocida, this paper reports the development and fabrication of a DNA-based electrochemical biosensor by integrating zinc oxide (ZnO) nanorods (NRs) into an electrochemical paper-based analytical device (ePAD). One significant improvement over the state-of-the-art features of the sensor is the using paper, an economically viable substrate that can be manufactured in large numbers. These sensors, being categorized under precision instruments with an ecologically friendly design, are ideal for mass production of eco-sensitive substrates. The biosensor is more sensitive and specific as compared to the conventional PCR-based sensing techniques. Moreover, the biosensor exploits the inherent properties of ZnO-NRs to amplify the signal output, whereas ePAD limits detection cost. In addition, a probe targeting the KMT gene of P. multocida was first characterized using conventional PCR and then immobilized onto the ZnO nanorods-modified ePAD surface, which improved the biosensor's ability for the rapid and selective genetic material of the pathogen detection. In addition, the sensor was validated using the methods of Cyclic Voltammetry (CV) and Linear Sweep Voltammetry (LSV). The reported biosensor it provides Linear Response of 0.001-10 μg/ml with LOD 0.001 μg/ml within a response time of 30 s. Subsequently, the biosensor reveals fast kinetics of the reaction as a powerful tool for timely and accurate diagnostics, pointing to its contribution to further development in biosensing technologies in the diagnostic area of infectious diseases at hospitals and clinics.

Development of a Radio Frequency Biosensor for the Characterization of Organic Materials

Development of a Radio Frequency Biosensor for the Characterization of Organic Materials

Development of fluorescence lifetime biosensors for ATP, cAMP, citrate, and glucose using the mTurquoise2-based platform

Development of fluorescence lifetime biosensors for ATP, cAMP, citrate, and glucose using the mTurquoise2-based platform

Tuning the performance of a TphR-based terephthalate biosensor with a design of experiments approach

Transcription factor-based biosensors are genetic tools that aim to predictability link the presence of a specific input stimuli to a tailored gene expression output. The performance characteristics of a biosensor fundamentally determines its potential applications. However, current methods to engineer and optimise tailored biosensor responses are highly nonintuitive, and struggle to investigate multidimensional sequence/design space efficiently. In this study we employ a design of experiments (DoE) approach to build a framework for efficiently engineering activator-based biosensors with tailored performances, and we apply the framework for the development of biosensors for the polyethylene terephthalate (PET) plastic degradation monomer terephthalate (TPA). We simultaneously engineer the core promoter and operator regions of the responsive promoter, and by employing a dual refactoring approach, we were able to explore an enhanced biosensor design space and assign their causative performance effects. The approach employed here serves as a foundational framework for engineering transcriptional biosensors and enabled development of tailored biosensors with enhanced dynamic range and diverse signal output, sensitivity, and steepness. We further demonstrate its applicability on the development of tailored biosensors for primary screening of PET hydrolases and enzyme condition screening, demonstrating the potential of statistical modelling in optimizing biosensors for tailored industrial and environmental applications.