Electrochemical Sensor Applications Research Articles

Co-Zn nanoparticles on N-doped graphene nanocomposites as bifunctional catalysts for non-enzymatic electrochemical sensor and organic dye degradation

Detection of biomolecules by advanced sensing systems and organic pollutant removal is of immense interest in biomedical and environmental remediation sectors. In this regard, effective glucose detection is dynamic in rapid-diagnosis of related diseases and in addition, removal of organic dyes by suitable adsorbent materials is vital for water treatment. The present work involves the facile fabrication of CoZn-N doped graphene nanocomposites and employed in glucose sensors and dye removal. The synthesized materials were characterized to evaluate the structural, morphological, elemental and surface characterizations such as, X-ray diffraction (XRD), Fourier transform infrared (FTIR), scanning DR-UV–vis–spectroscopy, electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), transmission electron microscopy (TEM) techniques, X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. SEM and TEM images revealed the Co-Zn nano particles (NPs) with respective morphologies within the N doped graphene structure. Electrochemical examinations of CoZn-N doped graphene nanocomposites/GCE sensor demonstrated superior sensitivity for the detection of commercial glucose in NaOH. Moreover, CoZnNG nanocatalyst has been investigated for the dye removal of crystal violet (CV), Rhodamine B (RB), methylene blue (MB) and congo red (CR) in the presence of H2O2. CoZnNG catalyst exhibited a maximum efficiency of 96 % over CV dye degradation in 30 min which is comparatively higher than the removal of MB, CR and RB dyes with 36 %, 41 %, 38 % for 120, 60 and 100 min, respectively. The CoZn-N doped graphene nanocomposites exhibited regeneration, reproducibility, and stability toward dye removal. Such multi-component hybrid N doped graphene could be efficacious for real-time non-enzymatic electrochemical sensor and pollutant removal applications.

Chemical vapor deposition-grown single-layer graphene-supported nanostructured Co3O4 composite as binder-free electrode for asymmetric supercapacitor and electrochemical detection of caffeic acid

In this study, we developed a monolayer graphene/nanostructured cobalt oxide (MLG/Co3O4) composite for asymmetric supercapacitor and electrochemical sensor applications. The MLG was grown by chemical vapor deposition process and the Co3O4 nanostructures were electrodeposited on the MLG surface. Scanning electron microscopy proved that there were flower-like nanostructured Co3O4 densely electrodeposited on the MLG surface. At a current density of 3 mA cm−2, the MLG/Co3O4 composite produced an areal capacitance of 3.73 F cm−2. After 10,000 cycles, the composite electrode still had 93.6 % of its initial capacitance at 5 mA cm−2. The asymmetric system displayed an areal capacitance of 929 mF cm−2 at 4 mA cm−2 with good cycle stability. The asymmetric electrode produced a specific energy of 51 μWh cm−2 and a specific power of 11.1 mW cm−2. Cyclic voltammetric measurements demonstrated that the composite showed redox peaks at 0.48 eV and 0.09 eV toward the determination of CA. With a sensitivity of 0.13 µA/µM/cm2 and a limit of detection of 0.009 µM, the composite showed CA concentrations, ranging from 0.5 to 480 M. The composite displayed excellent selectivity and the current produced for the interfering compounds was exceedingly low. Using the composite electrode, the spiked CA in red wine and green tea samples recovered remarkably effectively.

Plant-based zinc nanoflowers assisted molecularly imprinted polymer for the design of an electrochemical sensor for selective determination of abrocitinib

The first electrochemical sensor application in the literature is described for the sensitive and selective determination of the selective Janus kinase (JAK)-1 inhibitor abrocitinib (ABR). ABR is approved by the U.S. Food and Drug Administration (FDA) for the treatment of atopic dermatitis. The molecularly imprinted polymer (MIP)-based sensor was designed to incorporate zinc nanoflower (ZnNFs)-graphene oxide (GO) conjugate (ZnNFs@GO), synthesized from the root methanolic extract (RME) of the species Alkanna cappadocica Boiss. et Bal. to improve the porosity and effective surface area of the glassy carbon electrode (GCE). Furthermore, the MIP structure was prepared using ABR as a template molecule, 4-aminobenzoic acid (4-ABA) as a functional monomer, and other additional components. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) were used to characterize the surface and structure of the synthesized nanomaterial and MIP-based surface. Among the electrochemical methods, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were preferred for detailed electrochemical characterization, and differential pulse voltammetry (DPV) was preferred for all other electrochemical measurements using 5.0 mM [Fe(CN)6]3–/4– solution as the redox probe. The MIP-based sensor, which was the result of a detailed optimization phase, gave a linear response in the 1.0 × 10–13 – 1.0 × 10–12 M range in standard solution and serum sample. The obtained limit of detection (LOD) and limit of quantification (LOQ) values and recovery studies demonstrated the sensitivity, accuracy, and applicability of the sensor. Selectivity, the most important feature of the MIP-based sensor, was verified by imprinting factor calculations using ibrutinib, ruxolitinib, tofacitinib, zonisamide, and acetazolamide.Graphical

Aminosilane assisted deposition of gold nanoparticles on Zn(OH)2 nanosheets and their application in electrochemical sensor

A facile and efficient method for systematical deposition of gold nanoparticles (AuNPs) on Zn(OH)2 nanosheets (NS) with different Zn and Au ratios was established in the presence of N-[3-(trimethoxysilyl)propyl]diethylenetriamine (TPDT silane), without adding any external reducing agents, at room temperature. Here, TPDT silane behaves as both a stabilizing and reducing agent. UV–vis absorption spectroscopy, transmission electron microscopy, high-angle annular dark-field scanning transmission electron microscopy-energy dispersive X-ray spectroscopy, X-ray diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy were used to confirm the formation of AuNPs on Zn(OH)2 NS. As the concentration of AuNPs increased, a proportional increase in both the number and size of deposited AuNPs on Zn(OH)2 NS was observed. To understand how the variation in the number and size of AuNPs affects their catalytic activity, the electrocatalytic activity of different composition ratios of Zn(OH)2-Au NS toward nitrite ions was studied using cyclic voltammetry and amperometric technique. The TPDT-stabilized Zn(OH)2-Au NS showed high electrocatalytic activity, attributed to the effective electron transfer from Zn(OH)2 NS to AuNPs, creating a synergistic effect that enhances the overall activity. The optimal Zn(OH)2-Au NS modified electrode showed an amperometric sensitivity of 5.72 nA/µM and a limit of detection of 1.2 µM for nitrite ions in water sample well below the guideline value of WHO. This demonstrates the practical applicability of this method for real-world water analysis.

Paper-Based Electrochemical (Bio)Sensors for the Detection of Target Analytes in Liquid, Aerosol, and Solid Samples.

The last decade has been incredibly fruitful in proving the multifunctionality of paper for delivering innovative electrochemical (bio)sensors. The paper material exhibits unprecedented versatility to deal with complex liquid matrices and facilitate analytical detection in aerosol and solid phases. Such remarkable capabilities are feasible by exploiting the intrinsic features of paper, including porosity, capillary forces, and its easy modification, which allow for the fine designing of a paper device. In this review, we shed light on the most relevant paper-based electrochemical (bio)sensors published in the literature so far to identify the smart functional roles that paper can play to bridge the gap between academic research and real-world applications in the biomedical, environmental, agrifood, and security fields. Our analysis aims to highlight how paper's multifarious properties can be artfully harnessed for breaking the boundaries of the most classical applications of electrochemical (bio)sensors.

Synthesis of citral-tryptamine fused selenium nanospheres (CT@SeNP's) and exploration of their anticancer, antibacterial, and electrochemical sensor applications

A broad spectrum of antibiotics with multiple mechanisms of action is urgently required to combat the growing public health threat posed by drug-resistant pathogenic microorganisms. Biomedical researchers have concentrated on creating novel antibacterial and anticancer therapies due to the limited availability of conventional antibacterial and anticancer medications. In this study citral-tryptamine molecule was synthesized and characterized using 1HNMR , 13CNMR , LCMS and FT-IR spectral techniques and various biological properties of synthesized molecules were investigated using several in silico approaches such as molecular docking, ADME, PASS analysis and bioactive score. Using citral-tryptamine molecule, selenium nanoparticles (CT@SeNP's) were synthesized and characterized using different spectral and imaging techniques such as UV–Visible spectra, SEM, FTIR, EDX, XRD and DLS. EDX and mapping were used to investigate the relevant atoms and their distribution. Three significant signals from the EDX corresponding to C atom (15.4 %), along with signals from the Se atom (80.9 %) and the N atom (3.7 %). CT@SeNP's showed excellent antibacterial property against MRSA. The minimum inhibitory concentration of CT@SeNP's was found to be 20±0.36 mm with a good zone of inhibition in a dose dependent manner. CT@SeNP's was treated with both normal and cervical cancer cell lines such as SiHa to investigate the dose optimization and cytotoxicity by MTT assay. The nanoparticle showed an IC50 value is 0.68 µM and the data strongly suggested that CT@SeNP's could have a high potential in future medication development against MRSA and cervical cancer cells. The proper development and manufacturing of electrocatalytic nanomaterials are essential for enhancing the performance of non-enzymatic electrochemical sensors. The electrochemical sensing of H2O2 was enhanced by nanocomposite CT@SeNPs, which have a low detection limit of 60.96 nM and can detect H2O2 in a wide range of concentrations, from 25 µM to 250 µM. Thus, an efficient sensing platform for non-enzymatic H2O2 detection was discovered by this investigation.

Ti3C2Tx/laser-induced graphene-based micro-droplet electrochemical sensing platform for rapid and sensitive detection of benomyl

The design and fabrication of high-performance electrode devices are highly important for the practical application of electrochemical sensors. In this study, flexible three-dimensional porous graphene electrode devices were first facilely fabricated using common laser ablation technique at room temperature. After then, hydrophilic two-dimensional MXene (Ti3C2Tx) nanosheet was decorated on the surface of the laser-induced graphene (LIG), resulting in disposable Ti3C2Tx/LIG electrode devices. After introducing Ti3C2Tx nanosheet, the electrochemical active area, electron transfer ability of LIG electrode device and its adsorption efficiency toward organic pesticide benomyl was significantly boosted. As a result, the fabricated Ti3C2Tx/LIG electrode device exhibited significantly enhanced electrocatalytic activity toward benomyl oxidation. Based on this, a novel and ultra-sensitive electrochemical platform for micro-droplet detection of benomyl was achieved in the range of 10 nM–6000 nM with detection sensitivity of 169.9 μA μM−1 cm−2 and detection limit of 5.8 nM. Considering the low-cost Ti3C2Tx/LIG electrode devices are rarely used for electrochemical analysis, we believed this research work will contribute to exploring the broader application of MXene/LIG electrode devices in the field of electrochemical sensing.

Recent progress in tannin and lignin blended metal oxides and metal sulfides as smart materials for electrochemical sensor applications.

Our technologically advanced civilization has made sensors an essential component. They have potential uses in the pharmaceutical sector, clinical analysis, food quality control, environmental monitoring, and other areas. One of the most active fields of analytical chemistry research is the fabrication of electrochemical sensors. An intriguing area of electroanalytical chemistry is the modification of electrodes using polymeric films. Due to their benefits, which include high adhesion to the electrode surface, chemical stability of the coating, superior selectivity, sensitivity, and homogeneity in electrochemical deposition, polymer-modified electrodes have attracted a great deal of interest in the electroanalytical sector. Conducting polymers are an important material for sensing devices because of their fascinating features, which include high mechanical flexibility, electrical conductivity, and the capacity to be electrochemically converted between electronically insulating and conducting states. Tannin or lignin nanomaterials can be an inter-linker leading to flexible and functional polymeric networks. There is a continuing demand for fast and simple analytical methods for the determination of many clinically important biomarkers, food additives, environmental pollutants etc. This review in a comprehensive way summarizes and discusses the various metal oxide and sulfide-incorporated tannin and lignin scaffolds using electrochemical sensing and biosensing.

Fabrication of a novel HKUST-1/CoFe2O4/g-C3N4 electrode for the electrochemical detection of ciprofloxacin in physiological samples

In this work, a novel HKUST-1/CoFe2O4/g-C3N4 electrode was successfully prepared via the hydrothermal method and the high-temperature calcination method, which can be applied as an electrochemical sensor for the precise detection of ciprofloxacin (CIP) in physiological samples. The novel electrode was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR), and its electrochemical performance was further evaluated via the cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. The results demonstrated that the HKUST-1/CoFe2O4/g-C3N4 electrode exhibited an optimal linear range of 0.05–180 μmol L−1 for the CIP detection, which demonstrated a low limit of detection (LOD) of 0.0026 μmol L−1 and a low limit of quantitation (LOQ) of 0.0087 μmol L−1, respectively. Additionally, the novel semiconductor sensors exhibited exceptional selectivity, stability and repeatability in the determination of CIP. The recovery rate of CIP was found to range from 98.00% to 104.00% in serum, with the relative standard deviations (RSD) below 2.62% (n = 5), while the recovery rate of CIP was found to range from 96.00% to 105.00%, with the RSD less than 3.23% (n = 5) in urine. The current study extends to the application of the semiconductor-based electrochemical sensors and offers a new approach for the clinical pharmaceutical analysis to ensure medication safety, which could provide valuable insights into the potential of semiconductor sensors for future clinical applications.

Atomically precise Pdm(SR)n nanoclusters for efficient hydrogen evolution reaction

Thiolate (SR) protected noble metal nanoclusters have grasped immense attention because of their promising applications in electrocatalysis, electrochemical sensors, photoluminescencse, supercapacitor and energy production. Among the noble metals, numerous reports have highlighted interesting results for Au25(SR)18, Au22(SR)18 and Ag44(SR)30 clusters but Pd and Pt nanoclusters are less addressed. Room temperature ionic liquids (RTIL) show enhanced electrocatalytic activity and stability as a binding matrix as compared to commercial binders like Nafion, Polyvinylidene fluoride (PVDF) and so on. Here, we have synthesised water-soluble thiolate 3-mercaptopropyl sulfonate (MPS) capped Palladium nanoclusters (Pd-MPS NCs). Further, Poly Acrylamide Gel Electrophoresis (PAGE), a separation technique was used to isolate size-dependent NCs and their electrocatalytic activity for the hydrogen evolution reaction (HER) with room temperature ionic liquid as a binding matrix was demonstrated. The electron microscope images of isolated Pd-MPS NCs from these three bands (obtained from PAGE separation) resulted with size ranges of 0.8-1.8 nm, 2-4 nm and 4.2-8 nm respectively. Among the three bands obtained from PAGE gel from the crude Pd NCs, the ultrasmall Pdm(SR)n NCs was isolated from the lower band resulted in high HER activity with less overpotential of 197 mV and a Tafel slope of 125.2 mV dec-1 as compared to Pd-MPS NCs obtained from the other two distinctive bands.

Passivation strategies for enhancing sensitivity and repeatability of microelectrode electrochemical sensors

The sensitivity and repeatability are crucial for the practical application of electrochemical sensors. Many studies have focused on sensing materials and electrode structure to enhance sensitivity and repeatability rather than insulating layers. In this paper, polyaniline (PANI) microelectrode arrays were prepared to explore the influence of the insulating layer on sensitivity and repeatability of electrochemical sensors. The effects of different types of insulating layers, the sizes of the electrodes, and the thicknesses of the insulating layers were studied by experiment and simulation. The research findings indicated that the kind of organic insulating layers (Polyimide (PI) and SU-8) did not have a significant effect on the performance of the sensors. However, as the electrode area increased, the PANI film deposited on the electrode exhibited improved uniformity and density, leading to significant improvements in sensitivity and repeatability of the sensors. Additionally, the thickness of the insulating layer also had a significant impact on the performance of the device. The microelectrode with thinner insulating layers exhibited improved performance in sensitivity, repeatability and signal-to-noise ratio. The research findings indicated that increasing the electrode size and reducing the thickness of the insulating layer led to a more uniform and dense PANI film, resulting in an array electrode that exhibits excellent performance and remarkable repeatability.

Common Transition Metal Oxide Nanomaterials in Electrochemical Sensors for the Diagnosis of Monoamine Neurotransmitter‐related Disorders

AbstractMonoamine neurotransmitters are essential for learning, mental alertness, emotions, and blood flow, among other functions. Fatal neurological disorders that signal the imbalance of these biomolecules in the human system include Parkinson's disease, myocardial infarction, Alzheimer's disease, hypoglycemia, Schizophrenia, and a host of other ailments. The diagnosis of these monoamine neurotransmitter‐related conditions revolves around the development of analytical tools with high sensitivity for the four major monoamine neurotransmitters namely dopamine, epinephrine, norepinephrine, and serotonin. The application of electrochemical sensors made from notable metal oxide nanoparticles or composites containing the metal oxide nanoparticles for the detection of these monoamine neurotransmitters was discussed herein. More importantly, the feasibility of the application of the ZnO, CuO, and TiO2 nanoparticle‐based electrochemical sensors for a comprehensive diagnosis of monoamine neurotransmitter‐related conditions was critically investigated in this review.

Evaluation of Upscaling the Selective Electrophoretic Deposition of Reduced Graphene Oxide on Miniaturized Au Interdigital Electrodes from Chip-to Wafer-Level

Today’s novel materials challenge the research industry to enhance the performance and to reduce the power consumption of microchips as well as to develop new sensor principles. All this applies pressure on the investigation of new economical mass production technologies for the integration into standard process sequences or on top of state-of-the-art CMOS devices. Since the discovery of graphene in 2004, many different variations have been investigated, thus the number of publications of graphene-based content grew from a few in 2004 exponential to 1.2 million only in 2019, according to Google Scholar analysis. The deposition of graphene-based materials at wafer-level is still difficult to do economically on standard SEMI wafers up to 8” diameter. In this publication, the selective electrophoretic deposition (EPD) of reduced graphene oxide flakes (rGO) will be shown. This technique is a very promising deposition method for large scale fabrication. The EPD of rGO particles is the only known way to create 3D surface topologies for an enhanced sensing area of electrochemical sensor applications e.g. biosensors. The electrical and chemical properties of this novel material provides a broad range of applications for possible sensor solutions [1, 2]. Firstly, the deposition will be shown on chip scale to gain optimum parameters in suspension preparation and EPD deposition time/voltage for a uniform particle deposition over the sensor area. Shortcuts from particles between the transmission lines or co-deposition on reference electrodes have to be avoided. This leads to a high selectivity in rGO particle deposition on Au-structures. Afterwards designs and experiments have been made on array level and a proof of concept wafer-level deposition with a low volume suspension is demonstrated. In previous work, the adhesion of rGO on Au structures in electrochemical sensors with a liquid flow, showed a migration of the deposited particles with the friction of the liquid [3]. Therefore, standard separation of particle agglomeration or splitting of primary particles with ultra sonic sonotrodes are not sufficient to gain highly concentrated suspensions with homogenous target particle distributions (< 0,5µm ≤ 1µm ≥ 5µm). For this reason, a novel particle crushing preparation by ball milling is introduced and enhanced selectivity with an improved adhesion is demonstrated. A full process of the preparation of the colloidal suspension with the definition of target particle sizes with an optimum zeta potential will be provided and the cathodic electrophoretic deposition shown [4, 5]. For the evaluation of the deposition experiments, stereo microscopy is used to reveal the selectivity on the interdigital electrode (IDE) structures (sensor area) and scanning electron microscopy (SEM) analysis is used to characterize particle sizes and 3D topography, in terms of primary and secondary particles (agglomerates). For this study, IDE structures with 15 different geometry variations (3µm to 15µm lines and spaces) are used that were manufactured [6] to evaluate the rGO deposition on chip level. A novel multisensory array design with eight sensing areas are presented, combined with wafer-level deposition as a proof of concept on a 200mm wafer.

Nanoparticle-based electrochemical sensing

Electrochemical sensing has emerged as a potent technique for detecting and quantifying various analytes due to its inherent sensitivity, simplicity, and potential for miniaturization. Leveraging their distinctive physicochemical properties, nanoparticles have sparked a revolution in electrochemical sensing, enhancing sensing platforms’ sensitivity, selectivity, and stability. This paper presents the background and significance of nanoparticle-based electrochemical sensing, along with the diverse applications of nanoparticles in science and engineering. The fundamental principles of nanoparticles in electrochemical sensing are explored, highlighting their unique advantages in electrocatalysis, charge transfer facilitation, and signal amplification. The applications of various types of nanoparticles in electrochemical sensing are discussed, elucidating the role of nanomaterials in designing advanced conduction strategies such as impedance spectroscopy, cyclic voltammetry, and amperometry.Furthermore, this review delves into the applications of nanoparticle-based electrochemical sensors across domains, including gas detection, environmental monitoring, and the field of biosensors. The practicality of these sensors in real-world scenarios is showcased through case studies, emphasizing their rapid response, high specificity, and potential for multi-analyte detection. The challenges and prospects of this field are also examined. Addressing nanoparticle stability, reproducibility, and scalability issues is crucial for the successful commercial translation of these sensing platforms. In conclusion, this review underscores the transformative impact of nanoparticles on the landscape of electrochemical sensing. Their multifunctionality, coupled with evolving conduction methodologies, promises to develop ultra-sensitive and reliable sensing platforms that contribute to advancements across various application domains. With the continuous evolution of nanoparticle synthesis techniques, electrochemical sensing is poised to achieve new frontiers of sensitivity and specificity.

Construction of hierarchical NiCo2 S4 /2D-Carbyne nanohybrid onto nickel foam for high performance supercapacitor and non-enzymatic electrochemical glucose sensor applications.

Synthesising and designing pseudocapacitive material with good electrochemical and electrocatalytic behaviour is essential to use as supercapacitor as well as non-enzymatic glucose sensor electrode. In this work, NiCo2 S4 nanoparticles decorated onto the 2D-Carbyne nanosheets are achieved by the solvothermal process. The as-prepared NiCo2 S4 @2D-Carbyne provides rich reaction sites and better diffusion pathways. On usage as an electrode for supercapacitor application, the NiCo2 S4 @2D-Carbyne exhibits the specific capacitance of about 2507 F g-1 at 1 A g-1 . In addition, the fabricated hybrid device generates an energy density of 52.2 Wh kg-1 at a power density of 1.01 kW kg-1 . Besides, the glucose oxidation behaviour of NiCo2 S4 @2D-Carbyne modified GCE has also been performed. The diffusion of glucose from the electrolyte to the electrode obeys the kinetic control process. Furthermore, the fabricated NiCo2 S4 @2D-Carbyne non-enzymatic glucose sensor exhibits a limit of detection of about 34.5 μM with a sensitivity of about 135 μA mM-1 cm-2 . These findings highlight the need to design and synthesis electrode materials with adequate electrolyte-electrode contact, strong structural integrity, and rapid ion/electron transport.

Micrometer-thick and porous nanocomposite coating for electrochemical sensors with exceptional antifouling and electroconducting properties

Development of coating technologies for electrochemical sensors that consistently exhibit antifouling activities in diverse and complex biological environments over extended time is vital for effective medical devices and diagnostics. Here, we describe a micrometer-thick, porous nanocomposite coating with both antifouling and electroconducting properties that enhances the sensitivity of electrochemical sensors. Nozzle printing of oil-in-water emulsion is used to create a 1 micrometer thick coating composed of cross-linked albumin with interconnected pores and gold nanowires. The layer resists biofouling and maintains rapid electron transfer kinetics for over one month when exposed directly to complex biological fluids, including serum and nasopharyngeal secretions. Compared to a thinner (nanometer thick) antifouling coating made with drop casting or a spin coating of the same thickness, the thick porous nanocomposite sensor exhibits sensitivities that are enhanced by 3.75- to 17-fold when three different target biomolecules are tested. As a result, emulsion-coated, multiplexed electrochemical sensors can carry out simultaneous detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleic acid, antigen, and host antibody in clinical specimens with high sensitivity and specificity. This thick porous emulsion coating technology holds promise in addressing hurdles currently restricting the application of electrochemical sensors for point-of-care diagnostics, implantable devices, and other healthcare monitoring systems.

Applications of carbon nanostructure-modified electrochemical sensors in biomedical and pharmaceutical analysis

Applications of carbon nanostructure-modified electrochemical sensors in biomedical and pharmaceutical analysis

Synthesis and Characterization of ZIF 67 Manganese Bimetal for Electrochemical Sensor Application

The field of sensor applications has witnessed substantial growth in diverse domains, including agriculture, food, oil, environment, and medicine. Among the varied methodologies employed, electrochemical methods stand out. The judicious selection of appropriate materials in this context significantly augments sensor efficiency. Zeolitic Imidazolate Framework 67 (ZIF 67), a highly porous material with an expansive surface area, offers facile synthesis, yet is impeded by limited conductivity. The introduction of additional metal derivatives has been reported to enhance its conductivity, with manganese, a transition metal, identified for its potential conductivity improvement and its influence on particle size. Thus, this paper aims to comprehensively explore the properties of manganese-modified ZIF 67, spanning structural, morphological, and electrochemical properties. Research findings indicate that manganese doping enhances crystallinity, as evident from X-ray diffraction analysis, while also impacting particle size (from x¯ 514.4 nm to 944 nm), as assessed through SEM measurements. Furthermore, electrochemical performance reveals heightened peak current during redox processes reaching ±64 µA, indicative of improved conductivity from the ZIF 67 (±13 µA) and the bare (±43 µA). In light of these outcomes, this material emerges as a promising candidate for electrochemical sensor development.

Synthesis of Tin Doped Copper Oxide Nanocomposites for Electrochemical Sensor Application

Abstract Poly (Tin-doped copper oxide nanocomposites modified glassy carbon electrode) (Poly (Sn-doped CuO nanocomposite)-MGCE) made sensors were confirmed by electrochemical finding of norepinephrine (NE). The Sn-doped CuO nanocomposites were made by precipitation technique. This nanocomposite was described through scanning electron microscope and X-ray diffraction methods. To find the doped properties of the Poly (Sn-doped CuO nanocomposite)-MGCE were studied by cyclic voltammetry studies. The above studies prove that the altered electrodes have wide electroactive external area, and the reduction and oxidation peak appeared at pH 7.4 supportive electrolyte concentration 0.2 M phosphate buffer solution. Poly(Sn-doped CuO nanocomposite)-MGCE as limit of detection was low value for NE was found to be 2.22 µM and the limit of quantification values for NE was appeared as 7.41 µM, wide linear range, high sensitivity (20 to 350 µM), functional to the injection mockup analysis and the attained outcomes are acceptable, excellent reproducibility displays excessive potential in practical applications.

Green combustion synthesis of multifunctional inorganic ZnO: Co2+ (1–11 mol%) nanoparticles: Electrochemical and photocatalytic applications

Aloe Barbadensis Miller (Aloe vera) gel fuel-assisted facile combustion synthesized novel ZnO:Co2+ nanoparticles were analysed for its multifunctional applications such as supercapacitors, sensors, and photocatalytic dye degradation. The PXRD pattern of ZnO was matched with DFT-based computational XRD pattern. The morphology of the prepared nanomaterial was tested using Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) techniques. Band gaps were estimated using the Kubelka-Munk function (K-M function) using diffuse reflectance spectra (DRS). The band gap was found to be a minimum ̴ 1.90 eV for ZnO: Co2+ (7 mol%) nanoparticles. Electrochemical properties of ZnO: Co2+ (1–11 mol%) nanoparticles based modified carbon paste electrodes were studied in KCl electrolyte using cyclic voltammetry (CV), Electrochemical impedance spectroscopy (EIS) and Galvanostatic charge–discharge (GCD). Enhanced and optimized electrochemical performance in terms of specific capacitance was observed for ZnO: Co2+ (7 mol%) electrodes for supercapacitor application. EIS shows minimum ESR value of 72 Ω and GCD shows ̴ 99 % cyclic stability over 1550 cycles for ZnO: Co2+ (7 mol%) electrode. Effect of low band gap on electrochemical properties were established and found that low band gap leads to high performance in electrochemical activities. Sensitive detection of paracetamol and glucose (1––7 mM concentration) was carried out using the ZnO: Co2+ (7 mol%) electrode, for electrochemical sensor application. Photocatalytic degradation of methylene blue (MB) & acid orange-8 (AO-8) dyes was carried out using ZnO: Co2+ (7 mol%) photocatalyst under sunlight including scavenging examinations. Under sunlight, 92.45 % of MB and 98.29 % of AO-8 dyes were degraded in 120 min. Overall, this paper reports, multifunctional applications (EDLC, Sensor and Photocatalysis) of toxic free green combustion synthesized ZnO: Co2+ (1–11 mol%) nanoparticles.