Development Of Electrochemical Sensors Research Articles

Recent Advances in Electrochemical Biosensors Targeting Stress Markers.

When the body experiences a change in its internal environment due to factors such as mood (euphoria, stress) and illness, it releases biomarkers in large quantities. These biomarkers are used for detecting a disease at its early stages. This involves the detection of insufficient quantities of biocomponents, which can be done by using nanomaterials, conventional materials, and biotechnology; thus, scientists can increase the sensitivity of electrochemical sensors. According to studies conducted in this area, electrochemical sensors have shown promise as a diagnostic tool due to their ability to identify and pinpoint illness biomarkers. The present review article was compiled to gather the latest information on electrochemical biosensors targeting stress markers. The authors searched scholarly databases like ScienceDirect, Pubmed, Medline, and Scopus for information on electrochemical biosensors targeting stress markers. In this article, we looked at the recent developments in electrochemical sensors for stress monitoring. Because of advances in nanomaterial and biomolecule processes, electrochemical biosensors have been developed with the sensitivity to detect several biomarkers in real-time in therapeutically relevant materials. This biomarker sensor strategy can analyze various biofluids (sweat, plasma, urine, and saliva).

Emerging trends in functional materials for electrochemical sensors in nicotine determination.

In the past year, there has been significant progress in the utilization of electrochemical strategies for the determination of harmful substances. Among those, the electrochemical determination of nicotine (NIC) has continued to be of significant interest ascribed to the global health concern of e-cigarette products, nowadays. Electrochemical sensors have become promising tools for the detection of NIC ascribed to their high sensitivity, selectivity, and ease of use. This review article provides a concise overview of the advanced developments in electrochemical sensors for NIC detection using modified functional materials such as carbon-based materials, metal-organic frameworks (MOF), MXene, polymer, and metallic based modifiers. The sensitivity of electrochemical sensors can be improved by modifying them with these conductive materials ascribed to their physical and chemical properties. The review also addresses the challenges and future perspectives in the field, including sensitivity and selectivity improvements, stability and reproducibility issues, integration with data analysis techniques, and emerging trends. In conclusion, this review article may be of interest to researchers intending to delve into the development of functional electrochemical sensors in future studies.

Convenient and Accurate Detection of Dopamine and Glucose by Modifying Carbon Fiber Electrodes

Fast, sensitive, and low-cost high-performance detectors have gradually become an indispensable tool for people to keep healthy, and sensors are the key devices of detection equipment. In this work, a ZnO nanocrystal modified carbon fiber electrode was prepared using a hydrothermal method, and on this basis, a galvanostatic point deposition method was used to load copper nanoparticles to prepare a sensor electrode. Scanning electron microscopy and X-ray diffraction were used to comprehensively analyze composition, morphology, and environmental adaptability of the prepared electrodes. The DPV test was used to verify the enhanced effect of ZnO nanorods on neurotransmitter detection. The ZnO/CF showed an obvious electrical signal (0.22 V, 4 × 10−5A) in the detection of dopamine (DA) solution, and the Cu-NPs/ZnO/CF also showed excellent detection results in the glucose detection experiment., providing two excellent examples for the development of low-cost electrochemical sensors. The electrodes can specifically detect DA in the presence of ascorbic acid and uric acid, and the detection limit of the electrode for detecting DA is about 0.4 μM. In addition, the Cu-NPs/ZnO/CF electrode successfully realized the enzyme-free detection of glucose, and the detection limit could reach 0.5 μM.

Amplifying Flutamide Sensing through the Synergetic Combination of Actinidia-Derived Carbon Particles and WS2 Platelets.

The development of electrochemical sensors for flutamide detection is a crucial step in biomedical research and environmental monitoring. In this study, a composite of Actinidia-derived carbon particles (CPs) and tungsten disulfide (WS2) was formed and used as an electrocatalyst for the electrochemical detection of flutamide. The CPs had an average diameter of 500 nm and contained surface hydroxyl and carbonyl groups. These groups may help anchor the CPs onto the WS2 platelets, resulting in the formation of a CPs-WS2 nanocomposite with a high surface area and a conducting network, enabling electron transfer. Using the CPs-WS2 composite supported at a glassy carbon electrode, a linear concentration range extending from 1 nM to 104 μM, a limit of detection of 0.74 nM, and a sensitivity of 26.9 ± 0.7 μA μM-1 cm-2 were obtained in the detection of flutamide in a phosphate buffer. The sensor showed good recovery, ranging from 88.47 to 95.02%, in river water samples, and exhibited very good selectivity in the presence of inorganic ions, including Al3+, Co2+, Cu2+, Fe3+, Zn2+, NO3 -, SO4 2-, CO3 2-, and Cl-.

Development of a microfluidic wearable electrochemical sensor for the non-invasive monitoring of oxidative stress biomarkers in human sweat

Oxidative stress is widely recognized as a pivotal factor contributing to numerous Central Nervous System (CNS) ailments. The concentrations of hydrogen peroxide (H2O2) and phosphorylated proteins within the human body serve as crucial indicators of oxidative stress. As such, the real-time monitoring of H2O2 and phosphorylated proteins in sweat is vital for the early identification, diagnosis, and management of diseases linked to oxidative stress. In this context, we present a novel microfluidic wearable electrochemical sensor by modifying the electrode with Prussian blue (PB) and loading sulfur-rich vacancy-containing molybdenum disulfide (MoS2-X) onto Multi-walled carbon nanotube (CNTs) to form coaxially layered CNTs/MoS2-X, which was then synthesized with highly dispersed titanium dioxide nanoparticles (TiO2) to synthesize CNTs/MoS2-X/TiO2 composites for the detection of human sweat H2O2 and phosphorylated proteins, respectively. This structure, with its sulfur vacancies and coaxial layering, significantly improved sensitivity of electrochemical sensors, allowing it to detect H2O2 in a range of 0.01–1 mM with a detection limit of 4.80 μM, and phosphoproteins in a range of 0.01–1 mg/mL with a threshold of 0.917 μg/mL. Furthermore, the miniature sensor demonstrates outstanding performance in detecting analytes in both simulated and real sweat. Comprehensive biosafety assessments have validated the compatibility of the electrode material, underscoring the potential of sensor as a reliable and non-invasive method for tracking biomarkers linked to CNS disorders. This microfluidic wearable electrochemical biosensor with high performance and biosafety features shows great promise for the development of cutting-edge wearable technology devices for tracking CNS disease indicators.

Progress in The Application of Flexible and Wearable Electrochemical Sensors in Monitoring Biomarkers of Athletes

AbstractAthletes continuously seek out creative methods and technologies to improve their physical fitness and overall performance. Wearable technology's progress offers a swift and eco‐conscious way to consistently observe physiological changes evidenced by biomarkers, stemming from an athlete's internal exertion or external workload. However, there is still a long distance to further understand the internal physiology of athletes which may bring hope to tailor training and recovery programs individually. The ongoing challenges faced by sports healthcare personnel are in finding biomarkers safely and continuously to control athletes' physical condition and tailor their recovery and eating patterns. The summary of this review encompasses the development of flexible and wearable electrochemical sensors. This article provides an overview of biofluids, commonly detected by wearable biochemical sensors and their mutual anatomical formations, with a focus on sweat and its associated biomarkers. Following this, its real‐world application in sports medicine becomes apparent, both theoretically and potentially. The paper ends by highlighting challenges and imagining the possible development of this exciting emerging field.

Fabrication of Curcumin-Based Electrochemical Nanosensors for the Detection of Environmental Pollutants: 1,4-Dioxane and Hydrazine.

This work reports the development of novel curcuminoid-based electrochemical sensors for the detection of environmental pollutants from water. In this study, the first set of electrochemical experiments was carried out using curcumin-conjugated multi-walled carbon nanotubes (MWCNT-CM) for 1,4-dioxane detection. The MWCNT-CM/GCE showed good sensitivity (103.25 nA nM-1 cm-2 in the linear range 1 nM to 1 µM), with LOD of 35.71 pM and LOQ of 108.21 pM. The second set of electrochemical experiments was carried out with bisdemethoxy curcumin analog quantum dots (BDMCAQD) for hydrazine detection. The BDMCAQD/GCE exhibited good sensitivity (74.96 nA nM-1 cm-2 in the linear range 100 nM to 1 µM), with LOD of 10 nM and LOQ of 44.93 nM. Thus, this work will serve as a reference for the fabrication of metal-free electrochemical sensors using curcuminoids as the redox mediator for the enhanced detection of environmental pollutants.

Development of electrochemical sensors based on silver nanoparticles electrodeposited on gold screen-printed electrodes: application to nitrate trace analysis in water

Abstract. A simple, reusable and sensitive electrochemical sensor based on a gold screen-printed electrode modified with silver nanoparticles has been developed for the detection of nitrate in water. Scanning electron microscopy, square wave voltammetry and electrochemical impedance spectroscopy were used to characterize the modification of the electrode surface. The modified electrode with different silver nanoparticle loadings was also tested, as well as the influence of scan rate on the reduction of nitrate. The sensor exhibited a wide linear response to nitrate from 100 to 1500 µM and a detection limit of 7.7 µM, which is significantly less than the maximum contaminant level admitted in drinking water (800 µM). The reproducibility, repeatability and selectivity of the sensor have also been examined. The suitability of the proposed sensor for real sample detection was successfully demonstrated via recovery studies performed in spiked tap water samples. The proposed approach was used to determine nitrate in freshwater, and the results were in good agreement with those obtained from a commercial nitrate sensor. These advantages make the developed sensor a promising alternative approach for integration into an online monitoring system for water monitoring.

Miniaturized Electrochemical Sensing Platforms for Quantitative Monitoring of Glutamate Dynamics in the Central Nervous System

Glutamate is one of the most important excitatory neurotransmitters within the mammalian central nervous system. The role of glutamate in regulating neural network signaling transmission through both synaptic and extra‐synaptic paths highlights the importance of the real‐time and continuous monitoring of its concentration and dynamics in living organisms. Progresses in multidisciplinary research have promoted the development of electrochemical glutamate sensors through the co‐design of materials, interfaces, electronic devices, and integrated systems. This review summarizes recent works reporting various electrochemical sensor designs and their applicability as miniaturized neural probes to in vivo sensing within biological environments. We start with an overview of the role and physiological significance of glutamate, the metabolic routes, and its presence in various bodily fluids. Next, we discuss the design principles, commonly employed validation models/protocols, and successful demonstrations of multifunctional, compact, and bio‐integrated devices in animal models. The final section provides an outlook on the development of the next generation glutamate sensors for neuroscience and neuroengineering, with the aim of offering practical guidance for future research.

Miniaturized Electrochemical Sensing Platforms for Quantitative Monitoring of Glutamate Dynamics in the Central Nervous System.

Glutamate is one of the most important excitatory neurotransmitters within the mammalian central nervous system. The role of glutamate in regulating neural network signaling transmission through both synaptic and extra-synaptic paths highlights the importance of the real-time and continuous monitoring of its concentration and dynamics in living organisms. Progresses in multidisciplinary research have promoted the development of electrochemical glutamate sensors through the co-design of materials, interfaces, electronic devices, and integrated systems. This review summarizes recent works reporting various electrochemical sensor designs and their applicability as miniaturized neural probes to in vivo sensing within biological environments. We start with an overview of the role and physiological significance of glutamate, the metabolic routes, and its presence in various bodily fluids. Next, we discuss the design principles, commonly employed validation models/protocols, and successful demonstrations of multifunctional, compact, and bio-integrated devices in animal models. The final section provides an outlook on the development of the next generation glutamate sensors for neuroscience and neuroengineering, with the aim of offering practical guidance for future research.

Sparfloxacin/Gold Nanoparticles Modified Electrochemical Sensor for the Determination of Dopamine

Background: The development of facile, reliable, and sensitive electrochemical sensors for neurotransmitter detection is of utmost importance in biomedical research. Objectives: In this study, we proposed a novel approach for the synthesis of gold nanoparticles (AuNPs) using sparfloxacin as a reducing and stabilizing agent and further utilized as-prepared AuNPs for the construction of an electrochemical sensor to detect dopamine. Methods: The synthesis of AuNPs was achieved through a simple method where sparfloxacin acted as both a reducing and stabilizing agent. The AuNPs were investigated by using UV-visible spectroscopy, field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), elemental mapping (Emap), and X-ray diffraction (XRD). Results: The synthesised AuNPs were used to develop an electrochemical sensor for the detection of dopamine molecules. The fabricated electrochemical sensor demonstrated remarkable sensitivity and selectivity toward dopamine sensing. This sensor exhibited a good linear detection of dopamine in micromolar concentrations. Moreover, the sensor showed excellent stability and reproducibility. Conclusion: This novel electrochemical sensor holds significant potential for practical applications in neuroscience and clinical diagnosis, offering a rapid and sensitive method for dopamine detection. The utilization of sparfloxacin/AuNPs provides a promising avenue for the development of advanced electrochemical sensors with enhanced performance and wider applications in the detection of other neurotransmitters and biomolecules.

Portable electrochemical sensor for adrenaline detection using CoNi-MOF-based CS-PAM hydrogel

The development of a portable smartphone-based electrochemical sensor for analyzing adrenaline levels in real samples can make a great contribution to the research community worldwide. In order to achieve this goal, the key challenge is to build sensing interfaces with excellent electrocatalytic properties. In this work, microspherical bimetallic metal–organic frameworks (CoNi-MOF) consisting of nanoclusters were first synthesized using a hydrothermal method. On this basis, the catalytic activity of pure chitosan-polyacrylamide hydrogel (CS-PAM) was modulated by adding different amounts of CoNi-MOF during the in-situ synthesis of CS-PAM. Finally, a portable electrochemical detection system based on CS-PAM was established for the detection of adrenaline. A series of resulting composite hydrogels with a large specific surface area, abundant active sites, and unique network structure facilitate the enrichment and catalysis of adrenaline molecules. Under optimal conditions, the analytical platform constructed by using CoNi-MOF-based CS-PAM has the advantages of a wide detection range (0.5–10 and 10–2500 μM), a low detection limit (0.167 μM), and high sensitivity (0.182 and 0.133 μA·μM·cm−2). In addition, the sensor maintains selective detection of the target in the presence of many different types of interferences, and the current response is not significantly reduced even after 60 cycles of testing. We strongly believe that the designed smart portable sensing can realize the accurate determination of adrenaline in complex systems, and this study can provide new ideas for the research of MOFs-based hydrogels in electrochemical analysis.

Conducting Polymers in Amperometric Sensors: A State of the Art over the Last 15 Years with a Focus on Polypyrrole-, Polythiophene-, and Poly(3,4-ethylenedioxythiophene)-Based Materials

Conducting polymers are used in a wide range of applications, especially in the design and development of electrochemical sensors. Their main advantage, in this context, is their ability to efficiently modify an electrode surface using the direct polymerization of a suitable monomer in an electrochemical cell, or by physical coating. Additionally, the conducting polymers can be mixed with further materials (metal nanoparticles, carbonaceous materials) to enhance conductivity and analytical features (linear range, limit of detection, sensitivity, and selectivity). Due to their characteristics, conducting polymer-based amperometric sensors are applied to the determination of different organic and inorganic analytes. A view of recent advances in this field focusing on pyrrole, thiophene, and 3,4-ethylenedioxythiophene as starting materials is reported.

An antifouling electrochemical biosensor using self-signal for Salmonella typhimurium direct detection in food sample

Eating food contaminated by foodborne pathogens can lead to illness. The development of electrochemical sensors for pathogen detection has received widespread attention. However, the analytical performance of electrochemical sensors is inevitably affected by the non-specific adsorption of molecules in the sample. Moreover, the external signal probes might be affected by the complex components in the sample accompanied with signal suppression. This work presents an electrochemical aptasensor for Salmonella typhimurium detection based on the self-signal of poly-xanthurenic acid and the antifouling ability of chondroitin sulfate. The detection time was 60 min. The linear range was from 101 to 107 CFU/mL, and the detection limit was 3 CFU/mL. The biosensors presented good repeatability and storage stability. And the biosensors has been successfully applied in milk and orange juice. This strategy is expected to be applied in the design of other antifouling biosensors, to achieve rapid detection of pathogens and ensure food safety.

Efficient 2-Nitrophenol determination based on ultra-sonochemically prepared low-dimensional Au-nanoparticles decorated ZnO-chitosan nanocomposites by linear sweep voltammetry

In this study, linear sweep voltammetry (LSV) was implemented for the sensitive detection of 2-nitrophenol (2-NP) in phosphate buffer solution (PBS) at pH 7.00 with lab-made nanocomposite materials for environmental remediation. Initially, a flat glassy carbon electrode (GCE) modified using the inorganic-organic binary Au-NPs@ZnO/CTSN(Chitosan) nanocomposites (NCs) was used as a working electrode (WE). The NCs of Au NPs@ZnO/CTSN were basically prepared by an ultra-sonochemical process and fabricated on a GCE using conducting coating binder such as PEDOT:PSS. Before the electrochemical examination, the Au NPs@ZnO/CTSN NC was fully characterized by Fourier Transform Infrared Spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FESEM), Energy-dispersive X-ray Spectroscopy (EDS), Brunauer-Emmett-Teller (BET), X-Ray Diffraction analysis (XRD), High-Resolution Transmission Electron Microscopy (HRTEM), and X-Ray Photoelectron Spectroscopy (XPS) to analyze the functional, morphological, structural, elemental, surface area, crystallinity, and binding energy analyses. A linear concentration range (LDR) of 2-NP from 15⁓150 μM was evaluated by LSV in room conditions. From the slope of the calibration curve, the sensor sensitivity was calculated and found to be 20.9905 μAμM−1cm−2. At signal/noise ratio of 3, the lower limit of detection (LOD) is obtained as 0.45 ± 0.023 μM. Additionally, pH optimization, sensor-probe characterization, stability, and validity are fully analyzed in identical conditions by LSV. Besides this, the assembled 2-NP sensor probe as Au NPs@ZnO/CTSN NCs/PEDOT:PSS/GCE for validity test was performed elaborately and found the reliable and satisfactory results. This is a new approach to the development of electrochemical sensors for environmental chemical analysis using an electrochemical process with gold-nanoparticle decorated ZnO-chitosan for the safety of environmental and healthcare fields on a broad scale.

Development of surface molecular-imprinted electrochemical sensor for palmitic acid with machine learning assistance

Palmitic acid (PA) is a kind of saturated high fatty acid, which is involved in physiological safety and food quality. A surface molecularly imprinted polymer (MIP) electrochemical sensor was prepared on MXene surface using dopamine (DA) as functional monomer. The electrode was modified with gold nanoparticles (AuNPs), ferrocene-graphene oxide-multiwalled carbon nanotubes (Fc-GO-MWCNT) composite to enhance the electroactive area and conductivity. The sensor was characterized by scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), electrochemical impedance spectroscopy (EIS) and Differential pulse voltammetry (DPV), respectively. The parameters concerning this assay and various regeneration conditions have been carefully studied. The sensor can detect PA in the range of 1 nM-1 mM (R2 = 0.995), the limit of detection (LOD) is 0.48 nM (S/N = 3), and the limit of quantification (LOQ) is 1.61 nM. The artificial neural network (ANN) model in machine learning is further used to analyze the data collected by the sensor. The results show that the back propagation (BP) neural network in ANN is more suitable for the intelligent analysis of PA. The practicality of the sensor was confirmed by detecting PA in pork samples. This is the first MIP-based electrochemical sensor for PA, and it has great potential in practical applications.

Recent advances in graphene oxide-based electrochemical sensors

Graphene oxide-based nanomaterials are garnering significant attention from various fields due to their unique physical and chemical properties, which make them attractive for myriad applications. This feature article stems from Dr. Aicheng Chen’s Lecture for the 2023 Ricardo Aroca Award of the Canadian Society for Chemistry and focuses primarily on the synthesis and applications of graphene oxide-based nanomaterials for electrochemical sensing. Graphene oxide (GO), reduced graphene oxide, and functionalized and doped GO-based nanomaterials are emerging as promising enablers of broad applications in electrochemical sensors. This is due to their distinctive functional groups and novel properties, which include high electrical conductivities, large surface areas, and enhanced catalytic activities. Several strategies for the synthesis of these nanomaterials are described in this feature article, encompassing the modified Hummers method, electrochemical, thermal, and microwave reactor methods. The characterization of these GO-based nanomaterials is highlighted, employing techniques such as scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, Raman, and X-ray photoelectron spectroscopy to study their morphologies, structures, and chemical compositions. The development of GO-based electrochemical sensors and their pharmaceutical, medical, environmental, and food safety applications are discussed. Further, the effects of these GO-based nanomaterials and different electrochemical techniques (e.g., cyclic voltammetry, square wave voltammetry, linear sweep voltammetry, and differential pulse voltammetry) on the performance of various electrochemical sensors are addressed.

Electrochemical detection of regorafenib using a graphite sheet electrode modified with nitrogen-doped reduced graphene oxide nanocomposite

Regorafenib (RGF) is a multi-kinase inhibitor drug used for treating various cancers, posing challenges for detection in biological samples due to low solubility and stability. This paper presents a novel electrochemical sensor based on a monolith reduced graphene oxide (M-RGO) nanocomposite modified graphite sheet electrode. M-RGO was synthesized via a hydrothermal method and characterized extensively. The electrochemical performance was assessed using cyclic voltammetry and differential pulse voltammetry. The sensor demonstrated exceptional electrocatalytic activity for RGF oxidation, featuring two linear response ranges (31 nM to 600 nM and 600 nM to 920 nM) with a detection limit of 1.7 nM. The sensor exhibited good selectivity, stability, and reproducibility. Successful application in determining RGF in human serum and urine samples demonstrated the potential of M-RGO nanocomposite as a promising material for the development of electrochemical sensors for pharmaceutical analysis.

Thiourea‐Modified Multiwalled Carbon Nanotubes as Electrochemical Biosensor for Ultra‐Precise Detection of Dopamine

Functionalized multi‐walled carbon nanotubes (MWCNTs) have enticed remarkable attention in the field of electrochemical sensing applications. Dopamine (DA) is a monoamine neurotransmitter released in the brain acting as a chemical messenger that communicates messages between nerve cells and the rest of the body. Therefore, there is a significant technological urge for the development of electrochemical sensors for DA in body fluids. In this context, nitrogen‐functionalized MWCNTs (TM‐CNT600) were fabricated by thermal annealing of carboxylic acid functionalized MWCNTs with thiourea at 600 oC under N2 atmosphere. The XPS spectrum reveals the presence of nitrogen‐containing functionalities in the as‐prepared TM‐CNT600. FTIR results show the presence of ‐OH, C‐N and C‐S functional groups. XPS further corroborates the FTIR results and quantifies the predominant functional groups in as‐prepared material. The material was investigated as a potential electrochemical sensor for the detection of dopamine (DA). In the case of TM‐CNT600/GCE, a linear relationship for DA concentration was observed in the range of 10.7 ‐ 24.2 μM with the limit of detection (LOD) of 1.42 μM using linear sweep voltammetry (LSV). These results highlight the potential of TM‐CNT600 modified GCE as an efficient sensor for the electrochemical detection of DA in body fluids.

Carbons confined silver nanoclusters decorated carbon fiber electrodes toward electrochemical sensor of dihydroxyphenol and heavy metal ions

The development of electrochemical sensors based on noble metals has presented remarkable opportunities and challenges for the detection of trace phenols and heavy metal ions. However, the high costs of precious metals hinder the practical implementation of electrode materials. Enhancing the utilization efficiency of precious metals on the electrode surface is a crucial step toward improving electrochemical sensors based on these valuable materials. In this study, the morphology and utilization rate of silver nanoparticles were regulated by decorating nanofilms with different dimensions on carbon fiber electrodes. Specifically, the polypyrrole-derived carbon film coating enabled the material to have a large electroactive area and silver loading capacity. Simultaneously, the limiting effect of graphene quantum dots formed silver nanoparticles into silver clusters and achieved excellent electrochemical detection performance for dihydroxyphenol and heavy metal ions. Compared with silver nanoparticles, silver clusters provide higher electrocatalytic power and atomic utilization of silver. This study provides technical support for the trace analysis of environmental pollutants.