The Ni nanoparticle embedded on mesoporous carbon nanorods were developed as an effective sensing platform for non-enzymatic glucose detection.
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•Nanorod-like Ni anchored onto porous ...carbon supports were prepared by a simple method.•Ni/NCNs hybrids were acted as an effective sensing platform for non-enzymatic glucose detection.•The novel Ni/NCNs hybrids will hold promise in development of electrode materials.
Transition metal doped carbon materials are recognized as promising sensing platforms for glucose detection. Herein, a simple strategy involving crystallinity, nanostructure engineering, and pyrolysis was developed for constructing well-defined Ni nanoparticle embedded on nanoporous carbon nanorods (Ni/NCNs). A three-dimensional nickel-based metal-organic framework (Ni-MOF) was used as both a self-sacrificing template and precursor. Due to the synergistic effects between the uniformly dispersed Ni nanoparticles and the nanoporous carbon matrix, the as-prepared Ni/NCNs exhibited remarkable electrochemical activity. The fabricated Ni/NCNs glucose sensor showed excellent electrocatalytic performance with ultra-low limit of detection, wide linear detection ranges, fast response times (within 1.6 s), superior stability, and anti-interference characteristics. Moreover, the Ni/NCNs sensing platform was successfully applied to analyze glucose concentrations in human blood samples. These results showed that Ni/NCNs hold potential applications in developing enzyme-free glucose sensors.
Alzheimer's disease (AD) is a progressive neurodegenerative disorder with a long latency in the "prodromal" stage, for which there are currently no effective treatments. It is generally accepted that ...accurate diagnosis and subsequent treatment in the early stages of AD may lead to better therapeutic outcomes. Detection of body fluid biomarkers is an effective strategy for early AD diagnosis. Among them, amyloid β(1–42) (Aβ42), as one of the most important biomarkers of AD, plays a key role in the progression of AD. Currently, electrochemical biosensors offer many advantages in monitoring Aβ42 because they are fast, portable, and capable of on-site analysis. This article provides an overview of the dynamics of Aβ42 levels in biological fluids as AD progresses, followed by a detailed description of the design and analytical performance of various electrochemical sensors. Finally, the challenges of electrochemical sensors for AD diagnosis are discussed, and prospects and trends are outlined.
A review of electrochemical biosensor assays for Aβ42, an important biomarker of Alzheimer's disease. Display omitted
•The dynamics of Aβ42 levels in biological fluids as AD progresses are overviewed.•Advances in the design and analytical performance of various electrochemical Aβ42 biosensors are reviewed.•The possibility of applying the sensor in the practical analysis is presented.•The challenges, prospects and trends of electrochemical biosensors for Aβ42 detection are discussed.
Electrochemical sensors play a significant role in the industry and in everyday life. There has been a strong demand for short reaction time, and for highly sensitive, selective, responsive, stable ...and efficient sensors. Due to their unique electrochemical, optical and mechanical properties, graphene-based composites have enhanced the development of a new generation of sensors. The main thrust of this review is to highlight the present and future research and development work in the area of graphene/metal oxides based sensors. This review: i) discusses the latest developments in graphene–metal oxides for electrochemical sensing applications such as toxic gases and biomolecules analysis, ii) highlights the sensing mechanisms in graphene–metal oxide-based devices, architectures of sensors and performance parameters, and iii) the review concludes with a brief overview of future developments in the field of sensors. This review aims to act as a reference for researchers in developing new sensors based on graphene.
•Graphene based composites have fueled the development of new generation of sensors.•The review introduces the development work in the area of graphene–metal oxides based sensors.•The review discusses the latest developments of graphene–metal oxides for various electrochemical sensing applications.
Construction of highly-active artificial nanozymes for pesticides detection has great significance of human health and ecological systems. Herein, we have successfully designed a two-step approach to ...synthesize the TAPB-DMTP-COF (hereafter denoted as COF-OMe, TAPB, 1,3,5-tris(4-aminophenyl)benzene; DMTP, 2,5-dimethoxyterephaldehyde; COF, covalent organic framework)@Valine integrated cerium oxide nanozymes (COF-OMe@Valine-CeO2) with phosphatase-like activities, which can cleave phosphate bonds (PO) of organophosphorus pesticides (OPs) for the formation of electroactive p-nitrophenol (p-NP). In detail, the Ce (IV)/Ce (III) species serve as the active sites to polarize and hydrolyze PO bond in OPs, and the excellent adsorption performance of porous COF-OMe toward OPs could promote the hydrolysis process of PO. Moreover, the efficient charge transfer at the covalent interface of COF-OMe@Valine-CeO2 also contributed to this excellent catalytic process. By virtue of those advantages, the COF-OMe@Valine-CeO2 electrochemical platform was successfully applied in methyl-paraoxon (MP) detection. The resulting electrochemical sensors displayed high sensitivity, a wide linear response range of 0.034–76 μmol/L, and low detection limits of 0.011 μmol/L for MP. The research not only provides a preparation method for COF with excellent nanozyme activity, but broadens some new insights for the design of highly efficient nanozymes for on-time detection for OPs.
•The COF-OMe@Valine-CeO2 nanocomposites were constructed through a two-step approach.•The mesopores of COF-OMe@Valine-CeO2 enabling efficient diffusion and capture of the MP.•The resulting COF-OMe@Valine-CeO2 showed sensitive detection of MP.•The proposed sensor presented a good sensitivity in real samples detection.
The versatile properties of ZnO micro- and nano- structures have resulted in many applications in piezotronics, biosensors and photocatalysis. However, ZnO can easily dissolve in aqueous fluids, ...potentially resulting in the release of reactive oxygen species and zinc ions at toxic concentrations. Such an issue can be solved by dispersing ZnO within biocompatible polymeric matrices to reduce the direct exposure to the aqueous fluid and control the release of zinc ions. Herein, this work explores tailored ZnO flowers/cellulose acetate photocatalytic composites at different ZnO weight percentages (1–15 wt%). The photocatalytic degradation of methylene blue dye under simulated solar light is studied, finding an optimal value of ZnO filler loading in the polymer (10 wt%), resulting from a compromise between the photodegradation efficiency and the hydrophobicity induced by ZnO flowers. The reusability of the composites is investigated, finding a surprising improvement in the photodegradation efficiency after the first cycle. Simulated solar light stimulation induces the controllable release of zinc ions in aqueous solution at ppm-levels from the composites at the optimal ZnO filler loading. Finally, the release of ionic species in the absence of light stimulation is found to be directly proportional to the ZnO-loading in the composite, as a result of its degradation in aqueous environments.
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•Freestanding Cellulose Acetate/ZnO flowers composites for solar photocatalysis.•Rapid photocatalytic degradation by ZnO flowers loading optimization.•Controlled Zinc release from the Cellulose Acetate/ZnO flowers composites.•Electrochemical Impedance Spectroscopy for monitoring composite stability.
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•The green synthesis methods of GCDs are outlined.•Natural resources as source in GCDs technology are reviewed.•Recent applications of GCDs in different sensors have been ...summarized.•Some issues of GCDs for further study have been proposed and discussed.
As a new “zero-dimensional” carbon nanomaterial, carbon dots (CDs) have a wide range of applications in the fields of biology, chemistry, food science, and energy, which are ascribed to their intrinsic merits of good biocompatibility, strong stability, high specific surface area, etc. Especially, green carbon dots (GCDs) prepared from natural resources have received widespread attention due to their unique advantages, including wide sources, cost-effective, eco-friendly, etc. Interestingly, the various properties of GCDs can be obtained from different synthetic methods, which including the hydrothermal synthesis, microwave-assisted synthesis, pyrolysis carbonization synthesis, chemical oxidation synthesis, and ultrasonic synthesis. In consideration of their unique properties, GCDs have shown tremendous potential in fluorescence sensors, colorimetric sensors, and electrochemical sensors. The article mainly reviews the preparation methods of natural resources-based GCDs and the applications of GCDs in sensors for the first time. What’s more, the challenges and future direction of research on the preparation of GCDs and their applications in sensors are also discussed.
Electroanalytical devices have entered into the entirely new phase due to the utilization of the nanomaterials for the fabrication of electrochemical sensors. Nanomaterials with controlled ...morphologies and better surface functionalization offer ultrasensitive and selective electrode surfaces for electrochemical detection. The recent literature search on the fabrication of electrochemical sensors clearly reveals a shift toward morphologically controlled and suitably functionalized electrode modifiers to achieve robust electrochemical sensors. This review is specifically focused on the recent trends in the utilization of the various nanomaterials as modifiers in electrochemical sensing. These materials include fullerene, carbon nanotubes, carbon nanohorns, graphene, 3D graphene, carbon quantum dots, nanostructured polymers, and morphologically controlled metal/non-metal nanostructures. Such materials have been applied in the form of wires, nanorods, nanoribbons, core-shell, nanohorns to improve the surface kinetics and specificity of the modified surface toward electroanalytical detection.
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•Recent trends in nanomaterial enabled electrochemical sensors are discussed.•Nanomaterials with controlled and directional morphologies are described.•The factors that improve the sensitivity and selectivity of nanomaterials modified electrodes are appraised.•The new technologies suitable for point of care sensing are highlighted.
Electroanalysis has obtained considerable progress over the past few years, especially in the field of electrochemical sensors. Broadly speaking, electrochemical sensors include not only conventional ...electrochemical biosensors or non‐biosensors, but also emerging electrochemiluminescence (ECL) sensors and photoelectrochemical (PEC) sensors which are both combined with optical methods. In addition, various electrochemical sensing devices have been developed for practical purposes, such as multiplexed simultaneous detection of disease‐related biomarkers and non‐invasive body fluid monitoring. For the further performance improvement of electrochemical sensors, material is crucial. Recent years, a kind of two‐dimensional (2D) nanomaterial MXene containing transition metal carbides, nitrides and carbonitrides, with unique structural, mechanical, electronic, optical, and thermal properties, have attracted a lot of attention form analytical chemists, and widely applied in electrochemical sensors. Here, we reviewed electrochemical sensors based on MXene from Nov. 2014 (when the first work about electrochemical sensor based on MXene published) to Mar. 2021, dividing them into different types as electrochemical biosensors, electrochemical non‐biosensors, electrochemiluminescence sensors, photoelectrochemical sensors and flexible sensors. We believe this review will be of help to those who want to design or develop electrochemical sensors based on MXene, hoping new inspirations could be sparked.
Despite the enormous development of instruments for analyzing a wide variety of compounds, applied in different fields such as health, environment or quality control, the demand for increasingly ...sensitive and selective techniques continues to grow. In this regard, efforts have been made to highlight more appropriate techniques. Electrochemical sensors based on molecularly imprinted polymers (MIPs) offer an interesting alternative since they allow reaching high sensitivity and selectivity and they are inexpensive and easily adaptable to miniaturization. The choice of the functional monomer in the synthesis of MIPs is based on its capacity to provide complementary interactions with the target molecules. The various excellent properties of chitosan, as a biosourced polymer, make it a promising alternative to conventional functional monomers. This review reports on the principle of the MIPs technique describing the different possible approaches in their synthesis. It aims to provide an overview of the value of using chitosan as a functional monomer by highlighting its applications in electrochemical sensors.
•Chitosan is a biosourced polymer composed of glycosamine units.•Due to its functional groups, chitosan could constitute the basis of molecularly imprinted polymers.•Twenty-four articles report MIP chitosan-based electrochemical sensors.•Many small molecules were detected with MIP chitosan-based electrochemical sensors.
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