ZIF-67 is a Co-based zeolitic imidazolate framework material with both redox metal active sites and organic functional groups. Single walled carbon nanohorns (SWCNHs) is a novel horn-shaped carbon ...nanomaterial with abundant carbon active sites and high conductivity. SWCNHs@ZIF-67 heterostructure composites were prepared by environmental-friendly method with ZIF-67 as core and SWCNHs as shell, then were fixed on the surface of glassy carbon electrode (GCE) to obtain the electrochemical sensing platform for detecting H2O2. The as-proposed sensor (SWCNHs@ZIF-67/GCE) demonstrates excellent electrocatalytic performance for the reduction of H2O2 with two linearity scopes (0.50–150 µM, 150–400 µM) and a low detection limit of 0.15 μM, which is attributed to the synergistic electrocatalytic effect between ZIF-67 and SWCNHs. The as-fabricated sensor was satisfactorily used for H2O2 analysis in plasma samples, revealing an immense potential application in vitro assay of H2O2.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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•SARS-CoV-2 detection and monitoring by different electrochemical sensors.•Sensors are based on targets viz., nucleocapsid, spike antigen, immuno-globulin and viral nucleic ...acids.•Voltammetric, impedimetric, and amperometric techniques are the best practices.•High sensitivity and low limit of detection are observed with electrochemical sensors.
Coronavirus (COVID-19), a deadly pandemic has spread worldwide and created many global health issues. Though methods of its detection are being continuously developed for the early detection and monitoring of COVID-19, still there is need for more novel methods. The presently used methods include rapid antigen tests, serological surveys, reverse transcription-polymerase chain reaction (RT-PCR), artificial intelligence-based techniques, and assays based on sensors/biosensors. Of all these, RT-PCR test has high sensitivity and specificity though it requires more time for testing and need for skilled technicians. Recently, electrochemical sensors have been developed for rapid monitoring and detection of SARS-CoV-2 from the patient’s biological fluid samples. This review covers the recently developed electrochemical sensors that are focused on the detection of viral nucleic acid, immunoglobulin, antigen, and the entire viral particles. In addition, we also compare and assess their detection limits, sensitivities and specificities for the identification and monitoring of COVID-19. Furthermore, this review will address the best practices for the development of electrochemical sensors such as electrode fouling, limit of detection/limit of quantification determination and verification.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The recent developments of MOF-based materials, especailly their structure-property relationship for advanced electrochemical sensing applications are systematically summarized in this review. The ...different strategies used for the rational design and controllable synthesis of versatile MOF-based materials based on the specific requirements of the final electrochemical sensing applications are also outlined.
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•Recent development in MOF-based materials for electrochemical sensor is reviewed.•The structure-property relationship are emphasized.•Strategies for improving the sensing performance are discussed.•The current challenges and perspectives in this research area are also discussed.
Metal-organic frameworks (MOFs) are surprisingly porous materials that have attracted enormous attention in recent years owing to their fascinating structures and widespread potential applications. In this review, the recent developments of MOF-based materials for advanced electrochemical sensing applications are systematically summarized. A detailed discussion about the structure-property relationship, and the different strategies used for the rational design and controllable synthesis of versatile MOF-based materials based on the specific requirements of the final electrochemical sensing applications are outlined. The challenges and opportunities of developing MOF-based materials as novel electrochemical sensing platform are also discussed. Hopefully, this review will provide some creative inspiration to advance future studies on MOF-based materials in this emerging field.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
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•The applications of MOFs and MOF composites in electrochemistry were discussed.•The relationship between nanostructures and performances has been summarized.•Developing high ...conductivity MOFs can improve their electrochemical performance.•MOF composites can significantly improve overall performances.
Metal-organic frameworks are a class of functional porous materials. In recent years, metal-organic frameworks have become a hot research topic in the field of electrochemistry because of their controllable morphology, abundant pores, high specific surface area and versatility. Herein, we summarize the latest developments of metal-organic frameworks and metal-organic framework composites as electrode materials or catalysts for electrochemical applications such as batteries, supercapacitors, electrocatalysts and electrochemical sensors. The morphological and electrochemical properties of these promising metal-organic framework materials for their future development are discussed. Finally, based on the reported literature, we propose the future direction of metal-organic frameworks and metal-organic framework composites in the field of electrochemistry.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
For the first time, a modified electrochemical sensor based on carbon paste was developed using biochar derived from the husks of Moringa oleifera pods to detect successfully and simultaneously ...carbendazim (CBZ) and carbaryl (CBR) pesticides. Biochar was obtained via pyrolysis at 400 °C, which required no additional activation or modification processes. The incorporation of the biochar modifier enabled the preconcentration of both pesticides under open potential circuit conditions, resulting in a significant enhancement in sensitivity compared to bare electrode. Under the optimized experimental conditions, the developed sensor exhibited excellent sensitivity to the target analytes, showing a linear relationship within the concentration range of 0.29–6.00 μM for CBZ and 29.9–502 μM for CBR. The limits of detection were calculated to be 0.12 μM for CBZ and 10.4 μM for CBR. The proposed method demonstrated remarkable selectivity for analytes even in the presence of diverse organic and inorganic species. Furthermore, the method was successfully applied to the determination of CBZ and CBR pesticides in various water matrices, including river, sea, drinking, and groundwater samples, without the need for any sample pretreatment, such as extraction or filtration. The observed recoveries ranged from 87% to 111%, indicating the efficiency and reliability of this method.
For the first time, a Moringa oleifera biochar-based electrochemical sensor was developed and employed to determine simultaneously carbendazim (CBZ) and carbayl (CBR) in water matrices. Display omitted
•For the first time, moringa biochar was applied as electrode modifier (MOB/CPE).•MOB/CPE was used to simultaneously determine carbendazim (CBZ) and carbaryl (CBR).•Water bodies were evaluated by MOB/CPE without the need for sample treatment.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
With the increasing demand for highly sensitive and selective glucose sensors in industrial, clinical and pharmaceutical sectors, sensing materials for glucose detection have attracted much attention ...worldwide. Due to the large surface area, fascinating physical and electrochemical properties, graphene‐based materials have been widely used as a unique class of promising electrode materials in electrochemical sensing applications, with the continuously growing academic and technological developments. In this review, we summarize the different preparation strategies for the synthesis of graphene‐based materials and the application in electrochemical detection of glucose, including enzymatic and nonenzymatic glucose sensors.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
With a facile solvothermal technique, ZnMn
O
microspheres were synthesized in this work, which were used as enzyme mimics for the electrocatalytic reduction of H
O
. The morphology, crystal phase and ...structure of the ZnMn
O
microspheres underwent characterization under X-ray diffraction spectroscopy, Raman spectroscopy, energy-dispersive spectroscopy, and scanning electron microscopy. The synthesized ZnMn
O
microspheres showed an average diameter of 2 μm with great crystallinity, and exhibited excellent catalytical activity towards H
O
electroreduction in alkaline media. The glassy carbon electrode modified by ZnMn
O
microspheres showed a linear amperometric response for H
O
in a wide concentration range of 0.02 ˜ 15 mM with detection limit of 0.13 μM under the optimized conditions. Besides, the sensor proposed here was successfully used to determine H
O
in milk, suggesting that ZnMn
O
microspheres can be used for non-enzymatic electrochemical sensor applications.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
4- Nitrophenol (4-NP) is a top rated hazardous environmental pollutant and secondary explosive chemicals. For the sake of ecology and environment safety, the catalytic reduction and detection of 4-NP ...is highly important. In this work, ɤ-Fe2O3-nitrogen doped rGO (ɤ-Fe2O3–N-rGO) nanohydrogel was synthesized by green hydrothermal method. The morphology and phase purity of prepared ɤ-Fe2O3–N-rGO nanohydrogel were confirmed by various analytical (SEM, TEM, XRD, and XPS) and electrochemical techniques. The morphological structure of ɤ-Fe2O3–N-rGO nanohydrogel confirmed that the nanocrystals are well covered over the 2D N-rGO layer. Further, ɤ-Fe2O3–N-rGO nanohydrogel was applied for the catalytic reduction and electrochemical detection of ecotoxic 4-NP. A low cost, ɤ-Fe2O3–N-rGO nanohydrogel displayed an excellent catalytic activity, high recyclability (>5 cycles) and high conversion efficiency of 4-NP to 4-Aminophenol (4-AP). In addition, ɤ-Fe2O3–N-rGO nanohydrogel modified GCE displayed a wide linear sensing range (0.1–1000 μM), and a low detection limit (LOD) of 0.1 μM with excellent sensitivity, high selectivity (<1.2%) and good stability (>4 weeks). The developed sensor electrode shows the low reduction potential of −0.3 V and −0.60 V for the determination of 4-NP. The proposed ɤ-Fe2O3–N-rGO nanohydrogel is promising catalyst for the detection and removal of toxic aromatic nitro compounds in real site applications.
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•A low cost ɤ-Fe2O3–N-rGO nanohydrogel was prepared via hydrothermal method.•ɤ-Fe2O3–N-rGO nanohydrogel exhibits a tremendous catalytic removal of 4-NP.•ɤ-Fe2O3–N-rGO nanohydrogel exhibits high reduction efficiency more than 5 cycles.•Sensor electrode shows the low detection potential (−0.3 V), (−0.60 V) for 4-NP.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Azo dyes as widely applied food colorants are popular for their stability and affordability. On the other hand, many of these dyes can have harmful impacts on living organs, which underscores the ...need to control the content of this group of dyes in food. Among the various analytical approaches for detecting the azo dyes, special attention has been paid to electro-analytical techniques for reasons such as admirable sensitivity, excellent selectivity, reproducibility, miniaturization, green nature, low cost, less time to prepare and detect of specimens and the ability to modify the electrode. Satisfactory results have been obtained so far for carbon-based nanomaterials in the fabrication of electrochemical sensing systems in detecting the levels of these materials in various specimens. The purpose of this review article is to investigate carbon nanomaterial-supported techniques for electrochemical sensing systems on the analysis of azo dyes in food samples in terms of carbon nanomaterials used, like carbon nanotubes (CNT) and graphene (Gr).
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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•Gold nanoparticles and zeolitic imidazolate framework-8 nanocomposites (Au@ZIF-8) were synthesized.•Au@ZIF-8/GCE possessed an excellent electrochemical performance to dopamine.•The ...proposed sensor exhibited acceptable stability and repeatability.
Gold nanoparticles and zeolitic imidazolate framework-8 nanocomposites (Au@ZIF-8) were synthesized through a simple hydrothermal method and used as an enzyme-free sensor for dopamine detection. Various characterizations were used to investigate the structure and morphology of Au@ZIF-8 nanocomposites. The electrochemical performance of Au@ZIF-8 nanocomposite modified glassy carbon electrode (Au@ZIF-8/GCE) was examined in 0.1 M phosphate-buffered saline with different concentrations of dopamine. Consequently, Au@ZIF-8/GCE possessed an excellent electrochemical catalytic performance to dopamine, having been reported to its wider linear range from 0.1 to 50 μM, lower detection limit of 0.01 μM (S/N = 3) and higher sensitivity of 6.452 μA mM−1 cm−2. The proposed sensor exhibited acceptable stability and repeatability due to the coupling effect of Au nanoparticles and ZIF-8. All the evidence suggested a potential application of Au@ZIF-8 nanocomposites in a non-enzymatic dopamine sensor.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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