Search

Self-assembled monolayers were first described in the 1980s and have now become ubiquitous in many interfacial technologies. In this account, we discuss different self-assembled monolayer systems, outlining their positives and negatives. We then overview other researchers' work and our own group's journey in using self-assembled monolayers to develop new concepts in sensing and addressing general challenges faced by many types of sensors. Finally, we reflect on some of the challenges monolayer chemistry needs to address to facilitate further use of this powerful surface chemistry in commercial devices. Self-assembled monolayers (SAMs) allow surfaces to be modified with molecular-level control to give surface-specific functionality. SAMs have provided fundamental insight into surface phenomena and found utility in a range of applications. This account outlines a variety of different SAM systems and their application in sensing. (Image credit: Essam M. Dief.) This article belongs to the 10th Anniversary Collection of RACI and AAS Award papers. [ABSTRACT FROM AUTHOR]

New technologies can help to achieve the sustainable development goals (SDGs) of the United Nations. We discuss the contribution of microfluidic electrochemical biosensors to advancing the SDGs. These sensors can be applied in various fields given their low cost, self-powering ability, environmental compatibility, ease of use, and small sample volume requirements. [ABSTRACT FROM AUTHOR]

The development of electrochemical sensors for detecting neurotransmitters using wearable electronics has recently gained significant attention due to their painless nature. However, such wearable electronics that enable topical sweat detection of neurotransmitters fall short in accuracy, as this does not reflect the actual physiological conditions. Interstitial fluid provides a more accurate and reliable medium for measuring neurotransmitter levels, closely paralleling those found in blood. In this scenario, the present work focuses on the development of flexible metal oxide-based microneedle array patches for minimally invasive detection of dopamine (DA). A polydimethylsiloxane (PDMS)-based microelectrode array was fabricated by transferring a master mold from a laser-punched stainless-steel template followed by Au sputtering. Next, the developed flexible electrode surface was modified with hydrothermally produced ZnO nanoparticles (ZNP) for DA detection. A 3 × 3 microneedle array platform showed sensitivity of 7.654 µA µM−1 towards DA concentrations in a clinically relevant range of 1–100 µM in phosphate-buffered saline (PBS) electrolyte (pH 8). This proof-of-concept microneedle array platform could serve as an initial step towards the development of a painless and facile way of monitoring DA levels. [ABSTRACT FROM AUTHOR]

With the rapid development of society, it is of paramount importance to expeditiously assess environmental pollution and provide early warning of toxicity risks. Microbial fuel cell–based self-powered biosensors (MFC-SPBs) have emerged as a pivotal technology, obviating the necessity for external power sources and aligning with the prevailing trends toward miniaturization and simplification in biosensor development. In this case, vigorous advancements in MFC-SPBs have been acquired in past years, irrespective of whether the target identification event transpires at the anode or cathode. The present article undertakes a comprehensive review of developed MFC-SPBs, categorizing them into substrate effect and microbial activity effect based on the nature of the target identification event. Furthermore, various enhancement strategies to improve the analytical performance like accuracy and sensitivity are also outlined, along with a discussion of future research trends and application prospects of MFC-SPBs for their better developments. [ABSTRACT FROM AUTHOR]

Antimicrobial resistance (AMR) poses a significant threat to global health, powered by pathogens that become increasingly proficient at withstanding antibiotic treatments. This review introduces the factors contributing to antimicrobial resistance (AMR), highlighting the presence of antibiotics in different environmental and biological matrices as a significant contributor to the resistance. It emphasizes the urgent need for robust and effective detection methods to identify these substances and mitigate their impact on AMR. Traditional techniques, such as liquid chromatography-mass spectrometry (LC-MS) and immunoassays, are discussed alongside their limitations. The review underscores the emerging role of biosensors as promising alternatives for antibiotic detection, with a particular focus on electrochemical biosensors. Therefore, the manuscript extensively explores the principles and various types of electrochemical biosensors, elucidating their advantages, including high sensitivity, rapid response, and potential for point-of-care applications. Moreover, the manuscript investigates recent advances in materials used to fabricate electrochemical platforms for antibiotic detection, such as aptamers and molecularly imprinted polymers, highlighting their role in enhancing sensor performance and selectivity. This review culminates with an evaluation and summary of commercially available and spin-off sensors for antibiotic detection, emphasizing their versatility and portability. By explaining the landscape, role, and future outlook of electrochemical biosensors in antibiotic detection, this review provides insights into the ongoing efforts to combat the escalating threat of AMR effectively. [ABSTRACT FROM AUTHOR]

The detection of pathogens in medical wastewater is crucial due to the high content of pathogenic microorganisms that pose significant risks to public health and the environment. Medical wastewater, which includes waste from infectious disease and tuberculosis facilities, as well as comprehensive medical institutions, contains a variety of pathogens such as bacteria, viruses, fungi, and parasites. Traditional detection methods like nucleic acid detection and immunological assays, while effective, are often time-consuming, expensive, and not suitable for rapid detection in underdeveloped areas. Electrochemical biosensors offer a promising alternative with advantages including simplicity, rapid response, portability, and low cost. This paper reviews the sources of pathogens in medical wastewater, highlighting specific bacteria (e.g., E. coli, Salmonella, Staphylococcus aureus), viruses (e.g., enterovirus, respiratory viruses, hepatitis virus), parasites, and fungi. It also discusses various electrochemical biosensing techniques such as voltammetry, conductometry, impedance, photoelectrochemical, and electrochemiluminescent biosensors. These technologies facilitate the rapid, sensitive, and specific detection of pathogens, thereby supporting public health and environmental safety. Future research may should pay more attention on enhancing sensor sensitivity and specificity, developing portable and cost-effective devices, and innovating detection methods for diverse pathogens to improve public health protection and environmental monitoring. [ABSTRACT FROM AUTHOR]

This research presents the development of an innovative electrochemical detection platform using a graphene-zinc oxide (G-ZnO) nanocomposite for the quantification of 17β-estradiol in milk. The G-ZnO nanocomposite, synthesized via a facile one-pot method, exhibited a unique wrinkled structure with a high specific surface area of 143 m²/g. Characterization through SEM, TEM, and XRD confirmed the effective integration of ultrafine ZnO nanoparticles onto graphene sheets. The electrochemical performance of the G-ZnO modified glassy carbon electrode was evaluated, revealing a notably low detection limit of 8.3 nM for 17β-estradiol, a significant improvement over traditional sensors. The sensor demonstrated a wide linear range of 0.05–100 μM and exceptional reproducibility with less than 3.5 % RSD over repeated measurements. Recovery studies in spiked milk samples yielded highly accurate results, with recovery percentages ranging from 97.8 % to 104.6 %. These findings underscore the potential of G-ZnO nanocomposites in creating sensitive, efficient, and reliable sensors for healthcare and environmental applications. [ABSTRACT FROM AUTHOR]

The dynamic monitoring of biomolecules that are part of cell membranes generally constitutes a challenge. Electrochemiluminescence (ECL) biosensor assemblies provide clear advantages concerning microscopic imaging. Therefore, this paper proposes and analyzes a quantum dots-based biosensor assembly. Thus, particular attention is granted to biomolecules that are part of cell membranes. Additionally, this paper describes and analyzes a quantum dots-based biosensor assembly, which is used to implement a fully functional color ECL visualization system that allows for cellular and biomolecular structures to be accurately visualized. The related nano-emitter allows the implementation of real-time bioimaging scenarios. Consequently, the proposed approach is thoroughly evaluated relative to the time-dependent evolution of biomolecules. It has been demonstrated that traditionally problematic structures, like the biomolecules that are part of cell membranes, can be studied and monitored relative to their time-dependent dynamic evolution using the proposed solution. The reported research process has been conducted in the realm of cooperation with a specialized biomedical engineering company, and the described results are expected to substantially support a better understanding of the biomolecules' time-dependent dynamic evolution. [ABSTRACT FROM AUTHOR]

This research presents the development of an innovative electrochemical detection platform using a graphene-zinc oxide (G-ZnO) nanocomposite for the quantification of 17β-estradiol in milk. The G-ZnO nanocomposite, synthesized via a facile one-pot method, exhibited a unique wrinkled structure with a high specific surface area of 143 m²/g. Characterization through SEM, TEM, and XRD confirmed the effective integration of ultrafine ZnO nanoparticles onto graphene sheets. The electrochemical performance of the G-ZnO modified glassy carbon electrode was evaluated, revealing a notably low detection limit of 8.3 nM for 17β-estradiol, a significant improvement over traditional sensors. The sensor demonstrated a wide linear range of 0.05–100 μM and exceptional reproducibility with less than 3.5 % RSD over repeated measurements. Recovery studies in spiked milk samples yielded highly accurate results, with recovery percentages ranging from 97.8 % to 104.6 %. These findings underscore the potential of G-ZnO nanocomposites in creating sensitive, efficient, and reliable sensors for healthcare and environmental applications.

Modern sensing technologies are highly required for health monitoring. In this respect, the development of small‐size, high‐performance, and self‐powered biosensors for detecting and quantifying disease markers in biofluids can bring crucial changes and improvements to the concept of health monitoring systems. Clinical trials identify a wide range of biomarkers in biofluids that provide significant health information. Research into novel functional materials with outstanding properties opens up new perspectives for fabricating new‐generation biosensors. Furthermore, energy conversion and storage units are investigated to integrate them into biosensors and develop self‐powered systems. Electrochemical methods are very attractive for applications in biosensor technology, both in terms of biomarker detection and energy generation. Here the recent achievements in research into self‐powered electrochemical biosensors to detect sweat and saliva biomarkers are presented. Potential biomarkers for efficient analysis of these fluids are discussed in light of their importance in identifying various diseases. The influence of electrode materials on the performance of sensors is discussed. Progress in developing operating strategies for self‐powered electrochemical monitoring systems is also discussed. A summary and outlook are presented, mentioning major achievements and current issues to be explored. [ABSTRACT FROM AUTHOR]

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Metal Organic Frameworks (MOFs) are an evolving category of crystalline microporous materials that have grabbed the research interest for quite some time due to their admirable physio‐chemical properties and easy fabrication methods. Their enormous surface area can be a working ground for innumerable molecular adhesions and site for potential sensor matrices. They have been explored in the last decade for incorporation in electrochemical sensor matrices as diagnostic solutions for a plethora of diseases. This review emphasizes on some of the recent advancements in the area of MOF‐based electrochemical biosensors with focus on various important diseases and their significance in upgrading the sensor performance. It summarizes MOF‐based biosensors for monitoring biomarkers relevant to diabetes, viral and bacterial sepsis infections, neurological disorders, cardiovascular diseases, and cancer in a wide range of real matrices. The discussion has been supplemented with extensive tables elaborating recent trends in the field of MOF‐composite probe fabrication strategies with their respective sensing parameters. The article sums up the future scope of these materials in the field of biosensors and enlightens the reader with recent trends for future research scope. This article is categorized under:Diagnostic Tools > BiosensingDiagnostic Tools > Diagnostic Nanodevices [ABSTRACT FROM AUTHOR]

Regardless of many years of research work and conducting numerous clinical studies, breast cancer (BC) continues to grow among women, threatening their lives and future. Currently, it affects more than 10% of women globally. Therefore, researchers have recently redirected their endeavors toward detecting BC at an early stage, recognizing its substantial impact on survival rates, and acknowledging its immense potential for providing effective cancer treatments at this early diagnosed disease stage. The utilization of biomarkerbased diagnostic techniques significantly contributes to the advancement of early detection and precision. A wide range of biomarkers is linked to every newly diagnosed BC case. Traditionally, breast cancer was diagnosed using a variety of techniques such as mammography, molecular imaging, and ultrasonography. These techniques had several drawbacks, drawing the attention of many scientists to developing new methods and strategies. Among these strategies, electrochemical biosensors have proven to be excellent alternatives to more complex and traditional detection strategies in terms of performance, accuracy, robustness, and a tremendous range of applications. In this review, the use of conventional methods for detecting BC as well as their challenges and shortcomings have been stated. Moreover, a deep discussion was given to the newly developed nanocomposite-based electrochemical bio-sensing approaches that have been exploited for the effective detection and quantification of breast cancer biomarkers. [ABSTRACT FROM AUTHOR]

Globally, people are in great threat due to the highly spreading of viral infectious diseases. Every year like 100–300 million cases of infections are found, and among them, above 80% are not recognized and irrelevant. Dengue virus (DENV) is an arbovirus infection that currently infects people most frequently. DENV encompasses four viral serotypes, and they each express comparable sign. From a mild febrile sickness to a potentially fatal dengue hemorrhagic fever, dengue can induce a variety of symptoms. Presently, the globe is being challenged by the untimely identification of dengue infection. Therefore, this review summarizes advances in the detection of dengue from conventional methods (nucleic acid‐based, polymerase chain reaction‐based, and serological approaches) to novel biosensors. This work illustrates an extensive study of the current designs and fabrication approaches involved in the formation of electrochemical biosensors for untimely identifications of dengue. Additionally, in electrochemical sensing of DENV, we skimmed through significances of biorecognition molecules like lectins, nucleic acid, and antibodies. The introduction of emerging techniques such as the CRISPR/Cas' system and their integration with biosensing platforms has also been summarized. Furthermore, the review revealed the importance of electrochemical approach compared with traditional diagnostic methods. [ABSTRACT FROM AUTHOR]

Multielectrode electrochemical biosensors promise on-the-spot inspection of target compounds in biofluids, reducing costs in personalized healthcare. However, sensor sensitivity may decrease after each use due to biofouling, where chemical attachments on sensor electrodes curtail sensing signals. Current biofouling characterization techniques rely on time-consuming offline tests and analysis, making them impractical for on-the-spot signal correction. Alternatively, we propose to statistically model and correct the biofouling-induced signal changes. However, in addition to biofouling, the signals are influenced by multiple sources of variation, each with different levels of impact. To effectively characterize and separate biofouling effects from the major sources of variability, we establish a multiresolution functional mixed-effect model based on domain knowledge. A biosensing signal is first decomposed into a smooth trend and local peaks. The smooth trend models the effects of population-level biofluid composition, as well as patient and electrode effects to isolate variability sources. Changes in local peak location and amplitude indicate biofouling. These local peaks are modeled using a sparse subset of high-order functional terms. By modeling the changes of those high-order terms, we can characterize and predict the biofouling between consecutive measurements. We propose a sequential parameter estimation procedure that ensures model identifiability. A nonparametric regression model is developed for biofouling prediction. The proposed strategy is validated through simulation and real case studies, effectively correcting biofouling-affected signals from new patients. [ABSTRACT FROM AUTHOR]

This work presents a novel approach for tailoring molecularly imprinted polymers (MIPs) with a preliminary stage of atom transfer radical polymerization (ATRP), for a more precise definition of the imprinted cavity. A well-defined copolymer of acrylamide and N,N′-methylenebisacrylamide (PAAm-co-PMBAm) was synthesized by ATRP and applied to gold electrodes with the template, followed by a crosslinking reaction. The template was removed from the polymer matrix by enzymatic/chemical action. The surface modifications were monitored via electrochemical impedance spectroscopy (EIS), having the MIP polymer as a non-conducting film designed with affinity sites for CA15-3. The resulting biosensor exhibited a linear response to CA15-3 log concentrations from 0.001 to 100 U/mL in PBS or in diluted fetal bovine serum (1000×) in PBS. Compared to the polyacrylamide (PAAm) MIP from conventional free-radical polymerization, the ATRP-based MIP extended the biosensor's dynamic linear range 10-fold, improving low concentration detection, and enhanced the signal reproducibility across units. The biosensor demonstrated good sensitivity and selectivity. Overall, the work described confirmed that the process of radical polymerization to build an MIP material influences the detection capacity for the target substance and the reproducibility among different biosensor units. Extending this approach to other cancer biomarkers, the methodology presented could open doors to a new generation of MIP-based biosensors for point-of-care disease diagnosis. [ABSTRACT FROM AUTHOR]

Electrochemical biosensors include a recognition component and an electronic transducer, which detect the body fluids with a high degree of accuracy. More importantly, they generate timely readings of the related physiological parameters, and they are suitable for integration into portable, wearable and implantable devices that are significant relative to point-of-care diagnostics scenarios. As an example, the personal glucose meter fundamentally improves the management of diabetes in the comfort of the patients' homes. This review paper analyzes the principles of electrochemical biosensing and the structural features of electrochemical biosensors relative to the implementation of health monitoring and disease diagnostics strategies. The analysis particularly considers the integration of the biosensors into wearable, portable, and implantable systems. The fundamental aim of this paper is to present and critically evaluate the identified significant developments in the scope of electrochemical biosensing for preventive and customized point-of-care diagnostic devices. The paper also approaches the most important engineering challenges that should be addressed in order to improve the sensing accuracy, and enable multiplexing and one-step processes, which mediate the integration of electrochemical biosensing devices into digital healthcare scenarios. [ABSTRACT FROM AUTHOR]

The detection of clinically important disease-specific biomarkers such as proteins, nucleic acids, antibodies, enzymes, viruses and circulating tumor cells is essential for understanding their role in disease diagnosis and prognosis. Thus, current clinical research aims at developing a biosensor for the ultrasensitive, reliable, and specific detection of these low-abundant biomolecules in bodily fluids including urine, saliva, and blood. Electrochemical biosensors are powerful devices that make it simple, quick, and affordable the detection of disease biomarkers in clinical diagnostics Peptides epitomize an intriguing group of biorecognition elements that can be linked to electrochemical transducers owing to their stability and selectivity concerning a target analyte. Moreover, they are amenable to facile synthesis and modification with designated functional groups, rendering them appropriate for the creation of innovative architectures for electrochemical biosensing systems. In this review, we provided an outline of the most recent developments in material designs, recognition systems, and strategy advancements related to fabricating peptide-based electrochemical biosensors for disease biomarker detection.

Microbial biofilms play a pivotal role in microbial infections and antibiotic resistance due to their unique properties, driving the urgent need for advanced methodologies to study their behavior comprehensively across varied environmental contexts. While electrochemical biosensors have demonstrated success in understanding the dynamics of biofilms, scientists are now synergistically merging these biosensors with microfluidic technology. This combined approach offers heightened precision, sensitivity, and real-time monitoring capabilities, promising a more comprehensive understanding of biofilm behavior and its implications. Our review delves into recent advancements in electrochemical biosensors on microfluidic chips, specifically tailored for investigating biofilm dynamics, virulence, and properties. Through a critical examination of these advantages, properties and applications of these devices, the review highlights the transformative potential of this technology in advancing our understanding of microbial biofilms in different settings.

Abstract Cost‐effective miniaturized electrodes that maintain a high electroactive surface area (ESA) are needed for the widespread deployment of point‐of‐care sensors. Cost‐effective methods are recently developed to fabricate nanoroughened microstructured gold electrodes (NR‐MSEs) with ultrahigh ESA. In this work, the effectiveness of NR‐MSEs for bioelectrochemical enzymatic sensors is evaluated. A glucose sensor is constructed by first casting onto NR‐MSEs a solution containing reduced graphene oxide decorated with gold nanoparticles, glucose oxidase, and glutaraldehyde, followed by a solution containing ferrocene, and a layer of chitosan to prevent the leakage of sensor components. A urea biosensor is also fabricated using Nafion as a cationic exchanger for the electropolymerization of polyaniline, followed by the deposition of a composite containing urease, bovine serum albumin, and glutaraldehyde. The limit of quantification for both biosensors is below clinically relevant concentrations of the analytes in biofluids, 0.67 mm for glucose and 1.70 mm for urea. The sensors exhibit excellent performance in complex matrixes (human blood serum and wine for glucose and human blood serum and urine for urea), with recovery for spiked analytes in the range of 92–108%. It is anticipated that NR‐MSEs will expedite the development of highly sensitive bioelectrochemical sensors for use in resource‐limited settings.

Magnetic Fe 3 O 4 /α-Fe 2 O 3 heterogeneous nanorods with the saturation magnetization of 69.5 emu/g were prepared via the hydrothermal and calcination-reduction process using β-FeOOH nanorods as precursor and galactose as the reducing agent. The average length and diameter of the nanorods were 81.6 nm and 23.9 nm, respectively. The surfaces of the heterogeneous nanorods were modified with PEI and HAuCl 4 , resulting in magnetic rod-like Fe 3 O 4 /α-Fe 2 O 3 @Au nanocomposites. By utilizing the Au–S effect, Apt/ssDNA hybrid double-strands were loaded onto Fe 3 O 4 /α-Fe 2 O 3 @Au nanocomposites to form Fe 3 O 4 /α-Fe 2 O 3 @Au-Apt/ssDNA biosensors capable of recognizing mucoprotein-1 (MUC1) mucoprotein. These biosensors could be magnetically assembled onto a magnetic glassy carbon electrode to create a "Turn off" type electrochemical biosensor. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV) techniques were used to evaluate the detection performance. Based on the change in DPV signals, the optimal concentrations of magnetic Fe 3 O 4 /α-Fe 2 O 3 @Au nanocomposites and Apt/ssDNA double-stranded probes were 12 mg/mL and 9 μM, respectively, while the optimal incubation time was 2 h. Under these conditions, the sensor exhibited a linear detection range of 0.1 pg/mL to 1500 pg/mL (R2 = 0.9988), with a limit of detection (LOD) of 0.1 pM and a limit of quantitation (LOQ) of 0.34 pM. The biosensor demonstrated excellent performance in terms of selectivity, reproducibility (RSD = 2.9 %), and stability. When actual serum samples diluted by a factor of 20 in PBS were tested, the recovery rate ranged from 95.65 % to 103.40 %, indicating that this approach for sensitive detection of MUC1 holds promising prospects. [ABSTRACT FROM AUTHOR]

Cancer stands as the reigning champion of life-threatening diseases, casting a shadow with the highest global mortality rate. Unleashing the power of early cancer treatment is a vital weapon in the battle for efficient and positive outcomes. Yet, conventional screening procedures wield limitations of exorbitant costs, time-consuming endeavors, and impracticality for repeated testing. Enter bio-marker-based cancer diagnostics, which emerge as a formidable force in the realm of early detection, disease progression assessment, and ultimate cancer therapy. These remarkable devices boast a reputation for their exceptional sensitivity, streamlined setup requirements, and lightning fast response times. In this study, we embark on a captivating exploration of the most recent advancements and enhancements in the field of electrochemical marvels, targeting the detection of numerous cancer biomarkers. With each breakthrough, we inch closer to a future where cancer's grip on humanity weakens, guided by the promise of personalized treatment and improved patient outcomes. Together, we unravel the mysteries that cancer conceals and illuminate a path toward triumph against this daunting adversary. This study celebrates the relentless pursuit of progress, where electrochemical innovations take center stage in the quest for a world free from the clutches of carcinoma. [ABSTRACT FROM AUTHOR]

AbstractLimiting and preventing oral diseases remains a major challenge to the health of populations around the world, so finding ways to detect early-stage diseases (e.g., caries, periodontal disease, and oral cancer) and aiding in their prevention has always been an important clinical treatment concept. The development and application of electrochemical detection technology can provide important support for the early detection and non-invasive diagnosis of oral diseases and make up for the shortcomings of traditional diagnostic methods, which are highly sensitive, non-invasive, cost-effective, and less labor-intensive. It detects specific disease markers in body fluids through electrochemical reactions, discovers early warning signals of diseases, and realizes rapid and reliable diagnosis. This paper comprehensively summarizes the development and application of electrochemical biosensors in the detection and diagnosis of common oral diseases in terms of application platforms, sensing types, and disease detection, and discusses the challenges faced by electrochemical biosensors in the detection of oral diseases as well as the great prospects for future applications, in the hope of providing important insights for the future development of electrochemical biosensors for the early detection of oral diseases. [ABSTRACT FROM AUTHOR]

MicroRNAs (miRNAs) are vital in regulating biological processes and serve as effective biomarkers for tumor diagnosis in clinical trials. However, current miRNA detection approaches either lack sensitivity and selectivity among similar sequences in complex biofluids, or require cumbersome instruments and tedious operations, making convenient miRNA testing challenging, especially in the field of point‐of care clinical diagnosis. Here, an ultrasensitive single metallic nanowire‐based biosensor with stem‐loop probes modified by redox substances for one‐step miRNA detection with single base detection resolution (RNA‐on‐Nanowire) is presented. Using miRNA‐16 as a proof‐of‐concept, the developed RNA‐on‐Nanowire biosensor demonstrates high sensitivity with a wide detection range of 10 am–1 pm and a low limit of detection (LOD) of 0.54 am in mock samples. Furthermore, the biosensor shows excellent selectivity to miRNA‐16 among various miRNAs with the detection capability of single base substitution. Moreover, the successful detection of miRNA in serum samples with an LOD of 0.89 am suggest the great potential of the RNA‐on‐Nanowire biosensor for clinical applications. Overall, the presented RNA‐on‐Nanowire biosensor holds advantages in small sample consumption, high sensitivity, high specificity, and excellent portability which provides a promising strategy to meet the point‐of‐care testing demand for diagnosis and prognosis of various genetic diseases. [ABSTRACT FROM AUTHOR]

Several electrochemical biosensors based on various enzyme inhibition effects have been designed; their laboratory prototypes have been manufactured and thoroughly investigated. It should be noted that such biosensors are adapted to large‐scale production technologies. A number of advantages and disadvantages of developed biosensors based on enzyme inhibition has been discussed. It is important that all developed biosensors are not opposite to traditional analytical methods, but complement them. This is an additional system of quick and early warning about the presence of toxic substances in the environment. Such systems can save time and money in emergencies due to the possibility of quick decision‐making on local environmental problems. If necessary, more accurate, but time‐consuming and expensive traditional methods could be used for further validation and additional research of samples previously tested by biosensors. [ABSTRACT FROM AUTHOR]

Proline is an important amino acid, which is crucial to plant growth and development. Accurate analysis of proline content is of great significance for understanding its physiological mechanism in plants. In this paper, according to the requirements for in‐situ detection in plants in precision agriculture, an electrochemical molecular imprinted polymers (MIP) sensor for determining proline in living plants was developed. Polypyrrole (PPy) was used as the functional monomer. To improve the performance of the MIP sensor, Au nanoparticles (NPs) were electrodeposited on the screen‐printed electrodes (SPEs) electrode. Thionine (Thi) was then electropolymerized on the SPEs to be used as an internal reference signal molecule. The MIP‐based proline sensor has the widest detection range of 1×10−16 −0.01 M. And its detection limit is the lowest (9.18 aM) so far. It was also used for measuring free proline in the leaves of living cucumber seedlings under salt stress. The MIP‐based proline sensor has an important prospect for detecting the physiological status of plants in situ and will play an important role in smart agriculture. [ABSTRACT FROM AUTHOR]

Breast cancer is the second most frequent cause of mortality for women and one of the most prevalent malignant tumors that jeopardize women's health and unfortunately its prevalence is rising globally. Breast cancer has been diagnosed and treated to date by employing frequently used techniques such as mammography, magnetic resonance imaging (MRI), molecular breast imaging (MBI), biopsy, enzyme-linked immunosorbent assay (ELISA), fluorescence hybridization, polymerase chain reaction (PCR), immunohistochemistry, and flow cytometry. Nevertheless, some of these techniques are relatively complex, time-consuming, and not cost-effective, and even the low sensitivity and specificity of some of these platforms have caused these approaches not to receive much attention from researchers and clinical experts. For early identification and monitoring of cancer recurrence, the detection of low quantities of cancer biomarkers with high sensitivity and reproducibility is essential. While the detection of breast cancer by traditional methods is expensive, invasive, time-consuming, and sometimes has incorrect results, the development of an affordable technique that can diagnose breast cancer qualitatively or quantitatively in its early stages is one of the basic needs in this field. Due to their selectivity and high sensitivity, easy and quick detection, and lack of need for costly and specialized instruments, electrochemical biosensors have drawn particular interest. Therefore, the electrochemical method is considered an alternative to detect breast cancer biomarkers. In this review, some designed or developed electrochemical sensors and the methods and strategies for making these sensors for early detection of breast cancer are reviewed. The limitations and challenges of these investigations and obstacles to the commercialization of these systems are examined.

The biochemical oxygen demand (BOD) is critical for assessing water quality, linking the quantity of biodegradable organic carbon with pollution levels. Electrochemical biosensors have shown great improvements over traditional BOD measurement methods by offering the advantages of simplicity, rapid response, high sensitivity, and real-time monitoring. In this review, we discuss different types of BOD electrochemical biosensors, including oxygen electrode-, microbial fuel cell (MFC)-, and microbial electrolysis cell (MEC)-type sensors, focusing on recent advances in microbial community composition, electrode materials, and optimization approaches. Moreover, current challenges in developing effective electrochemical biosensors for BOD detection are presented to meet diverse sample needs.

Regardless of many years of research work and conducting numerous clinical studies, breast cancer (BC) continues to grow among women, threatening their lives and future. Currently, it affects more than 10% of women globally. Therefore, researchers have recently redirected their endeavors toward detecting BC at an early stage, recognizing its substantial impact on survival rates, and acknowledging its immense potential for providing effective cancer treatments at this early diagnosed disease stage. The utilization of biomarker-based diagnostic techniques significantly contributes to the advancement of early detection and precision. A wide range of biomarkers is linked to every newly diagnosed BC case. Traditionally, breast cancer was diagnosed using a variety of techniques such as mammography, molecular imaging, and ultrasonography. These techniques had several drawbacks, drawing the attention of many scientists to developing new methods and strategies. Among these strategies, electrochemical biosensors have proven to be excellent alternatives to more complex and traditional detection strategies in terms of performance, accuracy, robustness, and a tremendous range of applications. In this review, the use of conventional methods for detecting BC as well as their challenges and shortcomings have been stated. Moreover, a deep discussion was given to the newly developed nanocomposite-based electrochemical bio-sensing approaches that have been exploited for the effective detection and quantification of breast cancer biomarkers.

The dynamic monitoring of biomolecules that are part of cell membranes generally constitutes a challenge. Electrochemiluminescence (ECL) biosensor assemblies provide clear advantages concerning microscopic imaging. Therefore, this paper proposes and analyzes a quantum dots-based biosensor assembly. Thus, particular attention is granted to biomolecules that are part of cell membranes. Additionally, this paper describes and analyzes a quantum dots-based biosensor assembly, which is used to implement a fully functional color ECL visualization system that allows for cellular and biomolecular structures to be accurately visualized. The related nano-emitter allows the implementation of real-time bioimaging scenarios. Consequently, the proposed approach is thoroughly evaluated relative to the time-dependent evolution of biomolecules. It has been demonstrated that traditionally problematic structures, like the biomolecules that are part of cell membranes, can be studied and monitored relative to their time-dependent dynamic evolution using the proposed solution. The reported research process has been conducted in the realm of cooperation with a specialized biomedical engineering company, and the described results are expected to substantially support a better understanding of the biomolecules’ time-dependent dynamic evolution.

Precise monitoring of neurotransmitters, such as dopamine (DA), is critical for understanding brain function and treating neurological disorders since dysregulation of DA implicates in a range of disorders, including Parkinson's disease (PD), schizophrenia, and addiction. This study proposes a multi‐deformable double‐sided (MDD) DA‐sensing probe with the three‐electrode system in all‐in‐one form for reliable real‐time monitoring of DA dynamics by integrating working, reference, and counter electrodes on a single probe. The proposed probe achieves high DA sensitivity and selectivity in virtue of enzyme immobilization on the 3D nanostructures grown on working electrode. Also, the serpentine design is employed for the electrodes to withstand in various deformations by achieving high stretchability and manage the stress induced on the probe. Experimental and computational analysis demonstrates an effective reduction in induced‐stress on the electrodes. The MDD DA‐sensing probe is implanted into the brain with success to enable real‐time, in vivo monitoring of DA levels in rodents. Furthermore, DA dynamic changes are monitored before and after treatment with L‐DOPA in hemi‐PD mice. This extremely deformable implantable probe has the potential for use in the study and treatment of neurodegenerative diseases, providing reliable monitoring of DA dynamics with minimal damage to brain tissue. [ABSTRACT FROM AUTHOR]

Here we report the development of a method for the electrochemical ultrasensitive detection of antibodies that couples the programmability and versatility of DNA‐based systems with the sensitivity provided by enzymatic amplification. The platform, termed Enzyme‐Linked DNA Displacement (ELIDIS), is based on the use of antigen‐DNA conjugates that, upon the bivalent binding of a specific target antibody, induce the release of an enzyme‐DNA hybrid strand from a preformed duplex. Such enzyme‐DNA hybrid strand can then be electrochemically detected with a disposable electrode with high sensitivity. We applied ELIDIS to demonstrate the sensitive (limit of detection in the picomolar range), specific and multiplexed detection of five different antibodies including three clinically relevant ones. ELIDIS is also rapid (it only requires two reaction steps), works well in complex media (serum) and is cost‐effective. A direct comparison with a commercial ELISA kit for the detection of Cetuximab demonstrates the promising features of ELIDIS as a point‐of‐care platform for antibodies detection. [ABSTRACT FROM AUTHOR]

The monitoring of stress levels in humans has become increasingly relevant, given the recent incline of stress-related mental health disorders, lifestyle impacts, and chronic physiological diseases. Long-term exposure to stress can induce anxiety and depression, heart disease, and risky behaviors, such as drug and alcohol abuse. Biomarker molecules can be quantified in biological fluids to study human stress. Cortisol, specifically, is a hormone biomarker produced in the adrenal glands with biofluid concentrations that directly correlate to stress levels in humans. The rapid, real-time detection of cortisol is necessary for stress management and predicting the onset of psychological and physical ailments. Current methods, including mass spectrometry and immunoassays, are effective for sensitive cortisol quantification. However, these techniques provide only single measurements which pose challenges in the continuous monitoring of stress levels. Additionally, these analytical methods often require trained personnel to operate expensive instrumentation. Alternatively, low-cost electrochemical biosensors enable the real-time detection and continuous monitoring of cortisol levels while also providing adequate analytical figures of merit (e.g., sensitivity, selectivity, sensor response times, detection limits, and reproducibility) in a simple design platform. This review discusses the recent developments in electrochemical biosensor design for the detection of cortisol in human biofluids. Special emphasis is given to biosensor recognition elements, including antibodies, molecularly imprinted polymers (MIPs), and aptamers, as critical components of electrochemical biosensors for cortisol detection. Furthermore, the advantages and limiting factors of various electrochemical techniques and sensing in complex biofluid matrices are overviewed. Remarks on the current challenges and future perspectives regarding electrochemical biosensors for stress monitoring are provided, including matrix effects (pH dependence and biological interferences), wearability, and large-scale production. [ABSTRACT FROM AUTHOR]

Few sensing platforms have become ubiquitous to enable rapid and convenient measurements at the point‐of‐care. Those, however, are "one‐off" technologies, meaning that they can only detect a single target and are hardly adaptable. In response, we plan to develop a sensing platform that can be extended to detect other classes of molecules and that affords rapid, convenient, continuous measurements directly in undiluted complex matrices. For this, we decided to rely on a host molecule that presents reversible interactions toward specific guest molecules to develop a new class of sensors that we coined "Electrochemical DNA‐host chimeras". As a proof‐of‐concept for our sensor, we decided to use cyclobis(paraquat‐p‐phenylene) ("blue box") that we attached on an electrode‐bound DNA to allow measurements of electron‐rich guests such as dopamine and aspirin. Doing so allows to promote host‐guest complex that could be quantified using blue box's electrochemistry. Because of this unique sensor architecture, we achieve, to our knowledge, the first reagentless, continuous and rapid (<5 min) host‐guest measurements in undiluted whole blood. We envision that given the library of electroactive host molecules that this will allow the development of a sensing platform for measurements of several classes of molecules in complex matrices at the point‐of‐care. [ABSTRACT FROM AUTHOR]

Streptomycin (STR) is a prominent example of aminoglycoside antibiotics. It is extensively used in various agricultural sectors against bacterial infections and to control pests. STR kills bacteria by reducing the fidelity of protein synthesis. However, its uncontrolled and incorrect application can result in the appearance of unwanted residues of STR in animal-derived foodstuffs (milk, meat and honey) that can lead to severe health issues in humans like developing bacterial resistance, nephrotoxicity, ototoxicity, and allergic reactions. High-performance liquid chromatography (HPLC), Liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS), and enzyme-linked immunosorbent assay (ELISA) are still the most widely applied techniques to detect the presence of antibiotics residues due to their high sensitivity. However, researchers are putting continuous efforts into developing suitable alternatives because lab-based methods are laborious and need trained personnel and costly equipment. Among various analytical devices, electrochemical biosensors (ECBs) are emerging as promising devices for fast, specific, sensitive, and on-site detection of STR. The present review article includes the main principles and the recent trends in the ECBs developed for STR. This review highlights the current materials applied for the biosensing, miniaturisation, and construction of portable devices to be available on-site. [ABSTRACT FROM AUTHOR]

Laser‐inducing provides a cost‐effective, easily‐manufacturable, and environment‐friendly approach to directly transfer carbon‐rich polymers into graphene materials, which attracts attention from various fields, such as sensors, electrocatalysts, micro‐supercapacitors, etc. Laser‐induced graphene (LIG) benefits from the intrinsic properties of graphene, for example, high conductivity, high electroactivity, and high specific area. In this work the potential of laser‐induced graphene in constructing an enzymatic electrochemical biosensing interface is evaluated. Here, a laminar‐structured laser‐induced graphene material is fabricated by laser engraving with polyimide. After deposition of the electron mediator ferrocene, a conjugated enzyme complex of bovine serum albumin‐glucose oxidase (BSA‐GOx) is modified on the laser‐induced graphene by cross‐linking. The fabricated glucose oxidase/ferrocene/LIG (GOx/Fc/LIG) biosensor achieves high sensitivity of 11.3 µA mM−1 cm−2), wide linear range of 0–11 mM, and low detection of limit of 0.04 µM. The LIG electrodes exhibit high flexibility with bending angle as high as 60° without observed conductivity change. The repeatability and robustness of the developed LIG biosensor in detection of real serum samples empower it with great potential in clinical implementation in the future. [ABSTRACT FROM AUTHOR]

The accurate and simultaneous detection of neurotransmitters, such as dopamine (DA) and epinephrine (EP), is of paramount importance in clinical diagnostic fields. Herein, we developed cerium–molybdenum disulfide nanoflowers (Ce-MoS2 NFs) using a simple one-pot hydrothermal method and demonstrated that they are highly conductive and exhibit significant peroxidase-mimicking activity, which was applied for the simultaneous electrochemical detection of DA and EP. Ce-MoS2 NFs showed a unique structure, comprising MoS2 NFs with divalent Ce ions. This structural design imparted a significantly enlarged surface area of 220.5 m2 g−1 with abundant active sites as well as enhanced redox properties, facilitating electron transfer and peroxidase-like catalytic action compared with bare MoS2 NFs without Ce incorporation. Based on these beneficial features, Ce-MoS2 NFs were incorporated onto a screen-printed electrode (Ce-MoS2 NFs/SPE), enabling the electrochemical detection of H2O2 based on their peroxidase-like activity. Ce-MoS2 NFs/SPE biosensors also showed distinct electrocatalytic oxidation characteristics for DA and EP, consequently yielding the highly selective, sensitive, and simultaneous detection of target DA and EP. Dynamic linear ranges for both DA and EP were determined to be 0.05~100 μM, with detection limits (S/N = 3) of 28 nM and 44 nM, respectively. This study shows the potential of hierarchically structured Ce-incorporated MoS2 NFs to enhance the detection performances of electrochemical biosensors, thus enabling extensive applications in healthcare, diagnostics, and environmental monitoring. [ABSTRACT FROM AUTHOR]

Abstract Enzymes and antibodies are widely available biorecognition elements in bioanalytical tools such as personal glucose monitoring (PGM) devices and lateral flow assays (LFA). Meanwhile, electrochemical aptamer‐based (EAB) sensors are promising affinity‐based bioanalytical tools with potential advantages over such conventional bioassays. However, several critical factors affect the stability of EAB sensors, pivotal for their commercialization including 1) electrode defects due to surface treatment methods, 2) hampering effects of redox molecules, 3) electrical potential‐induced aptamer detachment, 4) thermal‐induced monolayer solubilization, 5) biochemical/enzymatic degradation, 6) biofouling, and 7) inadequate statistical design and analysis in EAB sensor fabrication. Herein, antidotes for the obstacles are proposed by applying novel surface treatment methods, adapting redox molecule, tuning electrochemical tests, tweaking backfilling agents, and anti‐bio‐fouling coatings. Nonetheless, the obstacles are a driving force to clear pathways toward bringing EAB sensors to the market for therapeutic drug and metabolite monitoring, point of care sensors, macromolecule detection, and pathogen diagnostics.

Abstract Proline is an important amino acid, which is crucial to plant growth and development. Accurate analysis of proline content is of great significance for understanding its physiological mechanism in plants. In this paper, according to the requirements for in‐situ detection in plants in precision agriculture, an electrochemical molecular imprinted polymers (MIP) sensor for determining proline in living plants was developed. Polypyrrole (PPy) was used as the functional monomer. To improve the performance of the MIP sensor, Au nanoparticles (NPs) were electrodeposited on the screen‐printed electrodes (SPEs) electrode. Thionine (Thi) was then electropolymerized on the SPEs to be used as an internal reference signal molecule. The MIP‐based proline sensor has the widest detection range of 1×10−16 −0.01 M. And its detection limit is the lowest (9.18 aM) so far. It was also used for measuring free proline in the leaves of living cucumber seedlings under salt stress. The MIP‐based proline sensor has an important prospect for detecting the physiological status of plants in situ and will play an important role in smart agriculture.

The detection of pathogens in medical wastewater is crucial due to the high content of pathogenic microorganisms that pose significant risks to public health and the environment. Medical wastewater, which includes waste from infectious disease and tuberculosis facilities, as well as comprehensive medical institutions, contains a variety of pathogens such as bacteria, viruses, fungi, and parasites. Traditional detection methods like nucleic acid detection and immunological assays, while effective, are often time-consuming, expensive, and not suitable for rapid detection in underdeveloped areas. Electrochemical biosensors offer a promising alternative with advantages including simplicity, rapid response, portability, and low cost. This paper reviews the sources of pathogens in medical wastewater, highlighting specific bacteria (e.g., E. coli, Salmonella, Staphylococcus aureus), viruses (e.g., enterovirus, respiratory viruses, hepatitis virus), parasites, and fungi. It also discusses various electrochemical biosensing techniques such as voltammetry, conductometry, impedance, photoelectrochemical, and electrochemiluminescent biosensors. These technologies facilitate the rapid, sensitive, and specific detection of pathogens, thereby supporting public health and environmental safety. Future research may should pay more attention on enhancing sensor sensitivity and specificity, developing portable and cost-effective devices, and innovating detection methods for diverse pathogens to improve public health protection and environmental monitoring.