Construction Of Electrochemical Sensor Research Articles

Progress in MXenes and Their Composites as Electrode Materials for Electrochemical Sensing and Dye-Sensitized Solar Cells

In the present mini-review article, we have compiled the previously reported literature on the fabrication of MXenes and their hybrid composite materials based electrochemical sensors for the determination of phenolic compounds and counter electrodes for platinum (Pt)-free dye-sensitized solar cells (DSSCs). MXenes are two-dimensional (2D) materials with excellent optoelectronic and physicochemical properties. MXenes and their composite materials have been extensively used in the construction of electrochemical sensors and solar cell applications. In this paper, we have reviewed and compiled the progress in the construction of phenolic sensors based on MXenes and their composite materials. In addition, co1.unter electrodes based on MXenes and their composites have been reviewed for the development of Pt-free DSSCs. We believe that the present review article will be beneficial for the researchers working towards the development of phenolic sensors and DSSCs using MXenes and their composites as electrode materials.

Construction of electrochemical sensor of Cu2O-CuO-W3O-W2C composite material for rapid and sensitive detection of vanillic acid

Vanillic acid is a phenolic compound which has antioxidant properties and plays an essential role in the prevention of several degenerative diseases, including cancer and atherosclerosis. This work reports the development and application of a electrochemical sensor for vanillic acid detection by a composite material (Cu2O-CuO-W3O-W2C) using polyoxometal-based metal–organic frameworks (POMOFs) as precursor through thermal decomposition. The synthesized Cu2O-CuO-W3O-W2C have high electrical conductivity and excellent electrocatalytic performance. The electrochemical sensor displays a linear response between the current density and concentration of vanillic acid (50–1100 μM) with a lowest detection limit of 1.439 μM under optimal conditions. The sensor was also demonstrated for the determination of vanillic acid in different real samples (fruit juice and fruit peel) and satisfactory results were obtained.

Platinum-Selenopeptide Interfaces in Support of High Fidelity Electrochemical Biomarker Quantification in Complex Biological Matrices.

The real world applications of conventional antifouling biosensors based on gold-thiol (Au-S) interfaces are hampered by the progressive competitive displacement of key functionality by ubiquitous biothiols. To overcome this limitation, we introduce here novel platinum-selenium (Pt-Se) interfaces. Thiol displacement tests, antifouling analyses, and density functional theory calculations confirm markedly improved interfacial stability. This was then leveraged through the application of a seleno-multifunctional peptide platform, tailored to the detection of murine double minute 2, in biological samples. A derived amperometric sensing platform exhibited a notably lower detection limit and more accurate target quantification than that supported by analogous Au-S and Pt-S interfaces. We believe that this work broadens the scope of electrochemical sensor construction and holds significant promise for the development of high-fidelity impactful bioassay platforms.

Chitosan-Based Hydrogel Functionalized with Fe(II) Phthalocyanine for Butylated Hydroxyanisole Determination.

The synthesis of functional electrode sensing materials is the key to the construction of electrochemical sensors. A new hydrogel electrode sensing material was developed by incorporating Fe(II) phthalocyanine (FePc) into chitosan-based hydrogels. The chitosan-based hydrogel plays a crucial role in dispersing FePc nanoparticles uniformly and generating a stable environment for the redox reaction of butylated hydroxyanisole (BHA) on the electrode surface. Under optimized conditions, the prepared electrochemical sensor exhibited a detection range of 0.1-30 and 30-1000 μmol/L, with a detection limit of 0.035 μmol/L (S/N = 3). Moreover, this sensor demonstrated exceptional resistance to interference and maintained its stability. These findings suggest that the developed electrochemical sensor is promising for reliable detection of BHA in real samples, highlighting the potential of combining conductive hydrogels with functionalized metal phthalocyanines for accurate and rapid BHA determination.

Advanced electrochemical sensing of cyanuric acid: An integration of transition metal dichalcogenides, copper and diamond nanoparticles

In the present study, we demonstrate the synergistic effect of copper nanoparticles, tungsten disulfide, and diamond nanoparticles on the electrochemical detection of cyanuric acid, a compound conventionally employed for disinfection in aquatic recreational facilities such as swimming pools. First, copper nanoparticles were synthesized in-situ on a glassy carbon electrode through the electrochemical reduction of copper nitrate and their response towards cyanuric acid was assessed. In order to improve this response, we evaluated the inclusion of transition metal dichalcogenides nanosheets (MoS2, ReS2 or WS2), as well as diamond nanoparticles in the electrochemical sensor construction. These nanomaterials were incorporated onto the electrode via drop-casting from their respective suspensions. Specifically, the 2D transition metal dichalcogenide suspensions were obtained through a top-down exfoliation method, facilitated by ultrasonic assistance. After optimizing the arrangement of nanomaterials on the glassy carbon electrode to enhance cyanuric acid detection, we characterized the morphology of the resulting surfaces at each stage of electrode surface modification by atomic force microscopy and scanning electron microscopy. The optimized methodology revealed that the sensor response exhibited a linear relationship with cyanuric acid concentrations ranging from 0.077 to 0.70 mM with a detection limit of 23 µM. The sensor was applied to cyanuric acid determination in a swimming pool water sample, obtaining very good recoveries. The results are in good agreement with those obtained by HPLC-UV–vis measurements.

Biochar from sugarcane bagasse: Synthesis, characterization, and application in an electrochemical sensor for copper (II) determination

Biochar (BC) is a carbonaceous material obtained from the thermal decomposition of organic matter under limited oxygen supply that plays an attractive role in waste management. In this study, biochar was prepared from sugarcane bagasse, using pyrolysis temperatures from 300 to 700 °C, and chemically activated with HNO3. Structural characterizations showed that degradation increased as pyrolysis temperature increased. Furthermore, a higher number of functional groups were observed for the materials produced under the lowest temperatures. Chemical activation resulted in oxidation and nitration of carbonaceous structure, increasing the number of functional groups on the materials. All materials were evaluated for the construction of electrochemical sensors towards Cu2+ ions voltammetric determination. The material produced at 400 °C pyrolysis temperature and activated (BCA400) provided the most intense response, which can be related to the presence of one of the highest numbers of surface groups, such as oxygen groups, on it. A method for Cu2+ determination was successfully developed based on differential pulse adsorptive stripping voltammetry (DPAdSV). A linear dynamic range (LDR) from 1.0 to 15.0 μmol L−1 was achieved, with limit of detection (LOD) of 0.36 μmol L−1, and limit of quantification (LOQ) of 1.09 μmol L−1. The method was also adequate in terms of accuracy and precision, as well as selective against most cationic species commonly found in tap water. The analyte was determined in tap water samples, in natura and spiked with the maximum concentration allowed by Brazilian legislation, and successful recovery values were obtained. Therefore, biochar from sugarcane bagasse, an environmentally-friendly material, was successfully used to construct an electrochemical sensor and determining an environmental and health interest analyte.

Covalently bridge metals to biomass carbon for sensing DA and FA with high specificity and sensitivity

Due to the high catalytic activity and electrical conductivity, “transition metal-nonmetal” compounds have broad application prospects in the construction of electrochemical sensors. However, it is still a challenge to solve the problem of catalyst deactivation and slow electron transfer due to nanoparticle agglomeration's blockage of active sites. Here, we prepare a series of covalently bonded “C-M-O” bridge bonds on biomass carbon for the first time. The bridge bonds have a straight-like “electron path”, which shortens the electron transfer path and improves the electrical conductivity, and catalytic activity. The bridge bonds exhibit excellent catalytic activity even after being subjected to prolonged mechanical external forces. Besides, the bridge bonds can integrate a biosensor with MIP and exhibit excellent electrocatalytic performance, including high sensitivity, low detection limit, excellent stability, superior interference immunity, and the ability to accurately monitor DA and FA released from real samples and live cells in real time. The strategy of forming “C-M-O” bridge bonds based on covalently bonded supports provides a new perspective for solving the agglomeration of nanocatalysts blocking active site deactivation and improving electron transfer rate.

Biomass-Derived Carbon-Based Electrodes for Electrochemical Sensing: A Review.

The diverse composition of biomass waste, with its varied chemical compounds of origin, holds substantial potential in developing low-cost carbon-based materials for electrochemical sensing applications across a wide range of compounds, including pharmaceuticals, dyes, and heavy metals. This review highlights the latest developments and explores the potential of these sustainable electrodes in electrochemical sensing. Using biomass sources, these electrodes offer a renewable and cost-effective route to fabricate carbon-based sensors. The carbonization process yields highly porous materials with large surface areas, providing a wide variety of functional groups and abundant active sites for analyte adsorption, thereby enhancing sensor sensitivity. The review classifies, summarizes, and analyses different treatments and synthesis of biomass-derived carbon materials from different sources, such as herbaceous, wood, animal and human wastes, and aquatic and industrial waste, used for the construction of electrochemical sensors over the last five years. Moreover, this review highlights various aspects including the source, synthesis parameters, strategies for improving their sensing activity, morphology, structure, and functional group contributions. Overall, this comprehensive review sheds light on the immense potential of biomass-derived carbon-based electrodes, encouraging further research to optimize their properties and advance their integration into practical electrochemical sensing devices.

Electrochemical detection of isocarbophos in apple and cabbage with Ti3C2TX/arginine and serine-functionalized graphene quantum dot@gold nanostar aerogel and target cycle dual signal amplification

The paper reports one strategy for synthesis of Ti3C2TX/arginine and serine-functionalized graphene quantum dot@Au nanostar aerogel (Ti3C2TX/RS-GQD@Au). Positively charged RS-GQDs bound with negatively charged Ti3C2TX sheets to form Ti3C2TX aerogel. Then, HAuCl4 was in situ reduced with ascorbic acid in the presence of L-glutathione to form gold nanostars on Ti3C2TX sheets. The resulting Ti3C2TX/RS-GQD@Au shows one three-dimensional structure. The gold nanostars were homogeneously dispersed on Ti3C2TX sheets. Introduction of RS-GQD realizes construction of Schottky heterojunction. The presence of L-glutathione triggers an asymmetric structural evolution of gold nanocrystals and leads to more exposed high-index crystal facets. Unique structure achieves to high conductivity, structural stability and catalytic activity. Ti3C2TX/RS-GQD@Au was used for construction of electrochemical sensor for detection of isocarbophos coupled with target cycle amplification. The peak current at 0.27 V linearly increases with the increase of isocarbophos concentration between 1 × 10−11 and 8 × 10−16 M with 2.9 × 10−16 M of detection limit (S/N = 3). The analytical method provide advantage of sensitivity and specificity for detection of isocarbophos in apple and cabbage.

New conductive ink based on carbon nanotubes and glass varnish for the construction of a disposable electrochemical sensor

This work presents the manufacture of a new conductive ink based on glass varnish and carbon nanotubes, employed for the construction of an electrochemical sensor printed on polyethylene terephthalate (PET) sheets. In this context, the exploration of the electrochemical and analytical performance of this new, low-cost conductive ink is of great interest. The sensors prepared with the proposed ink were studied by cyclic voltammetry (CV) using ferrocenemethanol (FcMeOH) as a redox probe. The proposed sensor was applied for the detection of 3-nitro-l-tyrosine (3-NLT), a modified amino acid present in biological fluids that can serve as an indicator of oxidative stress, using square wave voltammetry (SWV). Under optimized conditions, the sensor presented a linear response ranging from 0.70 to 100.0 μmol L-1, with a limit of detection (LOD) of 0.53 μmol L-1. The sensor was applied in the analysis of 3-NLT in synthetic urine, and recovery values ranging from 95.2 to 106.0% were obtained. Also, an analytical curve in human blood serum was constructed to show the suitability of the method in complex matrices. Linear responses ranging from 3.0 to 100.0 μmol L-1 of 3-NLT and a LOD of 1.35 μmol L-1 were obtained. Furthermore, the device was simple to produce and presented a relatively low cost. The obtained data demonstrate that the developed ink showed satisfactory analytical application, corroborating with further investigations and the advance in the production of other conductive inks in laboratory settings.

Advances in Nanomaterials Integration in CMOS-Based Electrochemical Sensors: A Review

The monolithic integration of electrochemical sensors with instrumentation electronics on semiconductor technology is a promising approach to achieve sensor scalability, miniaturization, and increased signal-to-noise ratio. Such integration requires postprocess modification of microchips (or wafers) fabricated in standard semiconductor technology [e.g., complementary metal–oxide–semiconductor (CMOS)] to develop sensitive and selective sensing electrodes. This review focuses on the postprocess fabrication techniques for the addition of nanomaterials to the electrode surface, a key component in the construction of electrochemical sensors that has been widely used to achieve surface reactivity and sensitivity. Several CMOS-compatible techniques are summarized and discussed in this review for the deposition of nanomaterials such as gold, platinum, carbon nanotubes, polymers, and metal oxide/nitride nanoparticles. These techniques include electroless deposition, electrochemical deposition, liftoff, microspotting, dip-pen lithography, physical adsorption, self-assembly, and hydrothermal methods. Finally, this review is concluded and summarized by stating the advantages and disadvantages of these deposition methods.

Towards an Improved Electrocatalytic Material for Detection of Polyphenols Based on Transition Metal Phosphides Anchored on Reduced Graphene Oxide

The design of advanced materials with catalytic activity for detection of a target molecule is key to construct a sensitive electrochemical sensor. Transition metal phosphides (TMPs) have recently attracted substantial interest and are widely investigated as electrode material in the field of energy conversion/storage. TMPs have also been exploited for electrochemical sensing showing promising results for molecular detection. In this work, we report the preparation of a composite consisting of bimetallic cobalt−nickel phosphide (CoNiP) nanoparticles supported on reduced graphene oxide (rGO) and study the impact of phosphorization and presence of rGO on the electrochemical response using hydroquinone (HQ) as a model phenolic compound. The results show that the catalytic performance of CoNiP@rGO is a consequence of the synergetic interaction between different atoms of CoNiP and rGO, where P increases the proton concentration at the electrode interface favoring a catalytic mechanism where metal centers are oxidized. In the presence of rGO this effect is suppressed due to the formation of high valence states of CoNiP. The remarkable electrocatalytic performance may originate from the modulation of the electronic structure together with the large electroactive surface area and low electron-transfer resistance, enabling CoNiP@rGO to be a promising candidate for electrochemical sensor construction.

Film-forming, stable, conductive composites of polyhistidine/graphene oxide for electrochemical quantification of trace Pb2.

Nanomaterials with unique properties, such as good film-formation and plentiful active atoms, play a vital role in the construction of electrochemical sensors. In this work, an in situ electrochemical synthesis of conductive polyhistidine (PHIS)/graphene oxide (GO) composite film (PHIS/GO) was designed to construct an electrochemical sensor for the sensitive detection of Pb2+. Herein, GO as an active material can directly form homogeneous and stable thin films on the electrode surface because of its excellent film-forming property. Then GO film was further functionalized by in situ electrochemical polymerization of histidine to obtain plentiful active atoms (N). Due to strong van der Waals forces between GO and PHIS, PHIS/GO film exhibited high stability. Furthermore, the electrical conductivity of PHIS/GO films was greatly improved by in situ electrochemical reduction technology and the plentiful active atoms (N) in PHIS are profitable for adsorbing Pb2+ from solution, tremendously enhancing the assay sensitivity. With the above unique property, the proposed electrochemical sensor showed high stability, a low detection limit (0.045 μg L-1) and a wide linear range (0.1-300 μg L-1) for the quantification of Pb2+. The method can also be extended to the synthesis of other film-forming nanomaterials to functionalize themselves and widen their potential applications, avoiding the addition of non-conductive film-forming substances.

Platinum nanoparticle-graphene quantum dot nanocage as a promising Schottky heterojunction electrocatalyst for electrochemical detection of vanillin in baby milk powder

Facile synthesis of platinum nanocrystal and its improvement in catalytic activity still face great challenges. The paper reports one strategy for synthesis of platinum nanoparticle-serine-functionalized and boron-doped graphene quantum dot composite (Pt-Ser-B-GQD). The Ser-B-GQD was prepared by pyrolysis of serine, boric acid and citric acid at 180 °C for 3 h and then reacted with chloroplatinic acid to form platiunm nanocrystal. The resultant Pt-Ser-B-GQD offers a nanocage-like structure composing of tiny graphene sheets connecting many ultrasmall platinum nanocrystals with an average particle size of 8.2 ± 0.32 nm. The combination of Pt nanocrystal with Ser-B-GQD results in the formation of Schottky heterojunction at the interface. The unique structure achieves to an improved catalytic activity. Pt-Ser-B-GQD was further used as Schottky heterojunction electrocatalyst for the construction of electrochemical sensor for the detection of vanillin. Because of excellent electrochemical properties, the sensor based on Pt-Ser-B-GQD exhibits a high sensitivity for electrochemical detection of vanillin. Differential pulse voltammetric peak current will increase linearly with increasing vanillin concentration in the range of 1 × 10−9-1 × 10−4 M with the detection limit of 2.8 × 10−10 Μ (S/N = 3). The proposed analytical method provides advantage of sensitivity, selectivity and reproducibility and was successfully applied in the detection of vanillin in baby milk powder.

Hydrothermal Synthesis of MnO2/Reduced Graphene Oxide Composite for 4-Nitrophenol Sensing Applications

Recently, the electrochemical sensing approach has attracted materials/electrochemical scientists to design and develop electrode materials for the construction of electrochemical sensors for the detection of para-nitrophenol (4-NP). In the present study, we have prepared a hybrid composite of MnO2 and rGO (MnO2/rGO) using a hydrothermal approach. The morphological features of the prepared MnO2/rGO composite were studied by scanning electron microscopy, whereas the phase purity and formation of the MnO2/rGO composite were authenticated via the powder X-ray diffraction method. Energy-dispersive X-ray spectroscopy was also employed to analyze the elemental composition of the prepared MnO2/rGO composite. In further studies, a glassy carbon electrode (GCE) was modified with MnO2/rGO composite (MnO2/rGO/GCE) and explored as 4-nitrophenol (4-NP) sensor. The fabricated MnO2/rGO/GCE exhibited a reasonably good limit of detection of 0.09 µM with a sensitivity of 0.657 µA/µMcm2. The MnO2/rGO/GCE also demonstrates good selectivity, stability and repeatability in 50 cycles.

GO/ZnO nanocomposite - as transducer platform for electrochemical sensing towards environmental applications

Graphene Oxide-Zinc Oxide (GO-ZnO) – a new nanomaterial that has queued the interest of researchers. Their intriguing promising physical and electrochemical features of electrode material have led to its widespread use in electrochemical sensor applications. GO-ZnO based nanomaterial were extensively exploited in the construction of electrochemical sensors due to their adaptability and distinct qualities. On understanding the structural role of these materials, their modification processes are critical for realizing their full potential. The advancement of technology on new concepts and strategies has revolutionized the field of sensor devices with high sensitivities and selectivity. These tools can test a range of contaminants quickly, accurately, and affordably while performing automated chemical analysis in complicated matrices. This paper highlights the electrochemical transducer surface for sensing various analytes and current research activity on GO-ZnO nanocomposite. Additionally, we talked about current developments in GO-ZnO nanostructured composites to identify relevant analytes (i.e., Nitrophenols, Antibiotic Drugs, Biomolecules). While being used in the laboratory, the majority of produced systems have proven to bring about excellent gains. Their monitoring application still has a long way to go before it is fixed due to problems like technological advancements and multifunctional strategies to get around the challenges for improving the sensing systems.

The Biomass of Pig-Blood-Derived Carbon as a Novel Electrode Material for Hydrogen Peroxide Electrochemical Sensing

In the work, a pig-blood-derived mesoporous carbon (BC) was prepared as a novel Fe-N-C material for the electrochemical sensor to detect hydrogen peroxide. Because of the unique nanostructure of Fe-BCs with rough surface structure, hierarchical pores, and high graphitization degree, the Fe-BCs, as a kind of advanced electrode material, exhibited remarkable performance in electrocatalysis. The sensor based on Fe-BCs exhibited an extra-long range from c and a detection limit of 0.046 μM (S/N = 3). The synthesis of low-cost, advanced carbon-based electrode materials from environmentally friendly pig blood for electrochemical sensor construction is a promising approach.

Editorial: Electrochemistry in Latin America

Editorial: Electrochemistry in Latin America

Design and Application of Electrochemical Sensors with Metal-Organic Frameworks as the Electrode Materials or Signal Tags.

Metal–organic frameworks (MOFs) with fascinating chemical and physical properties have attracted immense interest from researchers regarding the construction of electrochemical sensors. In this work, we review the most recent advancements of MOF−based electrochemical sensors for the detection of electroactive small molecules and biological macromolecules (e.g., DNA, proteins, and enzymes). The types and functions of MOF−based nanomaterials in terms of the design of electrochemical sensors are also discussed. Furthermore, the limitations and challenges of MOF−based electrochemical sensing devices are explored. This work should be invaluable for the development of MOF−based advanced sensing platforms.

Construction of Electrochemical Sensors for Antibiotic Detection Based on Carbon Nanocomposites.

Excessive antibiotic residues in food can cause detrimental effects on human health. The establishment of rapid, sensitive, selective, and reliable methods for the detection of antibiotics is highly in demand. With the inherent advantages of high sensitivity, rapid analysis time, and facile miniaturization, the electrochemical sensors have great potential in the detection of antibiotics. The electrochemical platforms comprising carbon nanomaterials (CNMs) have been proposed to detect antibiotic residues. Notably, with the introduction of functional CNMs, the performance of electrochemical sensors can be bolstered. This review first presents the significance of functional CNMs in the detection of antibiotics. Subsequently, we provide an overview of the applications for detection by enhancing the electrochemical behaviour of the antibiotic, as well as a brief overview of the application of recognition elements to detect antibiotics. Finally, the trend and the current challenges of electrochemical sensors based on CNMs in the detection of antibiotics is outlined.