Hierarchical 3-dimensional nickel-iron nanosheet arrays on carbon fiber paper as a novel electrode for non-enzymatic glucose sensing

Enhancement of Ni-NiO-CeO2 Interaction on Ni-CeO2/Al2O3-MgO Catalyst by Ammonia Vapor Diffusion Impregnation for CO2 Reforming of CH4

Ni-based catalysts have been widely used for the CO2 reforming of methane (CRM) process, but deactivation is their main problem. This study created an alternative electronic Ni-NiO-CeO2 interaction on the surface of 5 wt% Ni-5 wt% CeO2/Al2O3-MgO (5Ni5Ce(xh)/MA) catalysts to enhance catalytic potential simultaneously with coke resistance for the CRM process. The Ni-NiO-CeO2 network was developed on Al2O3-MgO through layered double hydroxide synthesis via our ammonia vapor diffusion impregnation method. The physical properties of the fresh catalysts were analyzed employing FESEM, N2 physisorption, and XRD. The chemical properties on the catalyst surface were analyzed employing H2-TPR, XPS, H2-TPD, CO2-TPD, and O2-TPD. The CRM performances of reduced catalysts were evaluated at 600 °C under ambient pressure. Carbon deposits on spent catalysts were determined quantitatively and qualitatively by TPO, FESEM, and XRD. Compared to 5 wt% Ni-5 wt% CeO2/Al2O3-MgO prepared by the traditional impregnation method, the electronic interaction of the Ni-NiO-CeO2 network with the Al2O3-MgO support was constructed along the time of ammonia diffusion treatment. The electronic interaction in the Ni-NiO-CeO2 nanostructure of the treated catalyst develops surface hydroxyl sites with an efficient pathway of OH* and O* transfer that improves catalytic activities and coke oxidation.

Advances of Transition Metal-Based Electrochemical Non-enzymatic Glucose Sensors for Glucose Analysis: A Review

Glucose concentration is a crucial parameter for assessing human health. Over recent years, non-enzymatic electrochemical glucose sensors have drawn considerable attention due to their substantial progress. This review explores the common mechanism behind the transition metal-based electrocatalytic oxidation of glucose molecules through classical electrocatalytic frameworks like the Pletcher model and the Hydrous Oxide-Adatom Mediator model (IHOAM), as well as the redox reactions at the transition metal centers. It further compiles the electrochemical characterization techniques, associated formulas, and their ensuing conclusions pertinent to transition metal-based non-enzymatic electrochemical glucose sensors. Subsequently, the review covers the latest advancements in the field of transition metal-based active materials and support materials used in non-enzymatic electrochemical glucose sensors in the last decade (2014-2023). Additionally, it presents a comprehensive classification of representative studies according to the active metal catalysts components involved.

A wearable AuNP enhanced metal-organic gel (Au@MOG) sensor for sweat glucose detection with ultrahigh sensitivity

The demand for sensitive and non-invasive sensors for monitoring glucose levels in sweat has grown considerably in recent years. This study presents the development of a wearable sensor for sweat glucose detection with ultrahigh sensitivity. The sensor was fabricated by embedding Au nanoparticles (AuNPs) and metal-organic gels (MOGs) on nickel foam (NF). A non-enzymatic electrocatalytic glucose sensor has been developed to combine the three-dimensional network of MOGs with more active sites favourable for glucose diffusion and the transfer of electrons from glucose to the electrode. These results show that the sensor has an ultrahigh sensitivity of 13.94 mA mM-1 cm-2, a linear detection range between 2 and 600 μM, and a lower detection limit as low as 1 μM (signal/noise = 3) with comparable accuracy and reliability under non-alkaline conditions to those of high-pressure ion chromatography (HPIC). Furthermore, a wearable sweat glucose sensor has been constructed by sputtering an Au conductive layer on a flexible polydimethylsiloxane (PDMS) substrate and coating it with Au@MOGs. Our work demonstrates that the combination of Au NPs and MOGs can enhance the sensitivity and activity of these materials, making them useful for electrocatalytic glucose monitoring with ultrahigh sensitivity.

Direct decoration of commercial cotton fabrics by binary nickel-cobalt metal-organic frameworks for flexible glucose sensing in next-generation wearable sensors

Having a prime significance in diagonsing and predicting the dangerous symptoms of chronic diseases in the early stages, special attention has been drawn by wearable glucose-sensing platforms in recent years. Herein, modified commercial cotton fabrics, decorated with binary Ni-Co metal-organic frameworks (NC-MOFs) through a one-pot scalable hydrothermal route, were directly utilized as flexible electrodes for non-enzymatic glucose amperometric sensing. Glucose sensitivities of 105.2 μA mM^-1 cm^-2 and 23 μA mM^-1 cm^-2 were acheived within two distinct linear dynamic ranges of 0.04-3.13 mM and 3.63-8.28 mM, respectively. Receiving benefits from a remarkable glucose sensitivity behavior in co-existence of iso-structures and interferences, rapid response (4.2 s), and remarkable reproducibility and repeatability, NC-MOF-modified cotton fabric electrodes are imensilly promising for developing high-performance wearable glucose sensing platfroms. The sensing performance of fabricated electrodes was further investigated in human blood serum and saliva.

Carbon Nanotube Fiber-Based Flexible Microelectrode for Electrochemical Glucose Sensors

Electrochemical sensors are gaining significant demand for real-time monitoring of health-related parameters such as temperature, heart rate, and blood glucose level. A fiber-like microelectrode composed of copper oxide-modified carbon nanotubes (CuO@CNTFs) has been developed as a flexible and wearable glucose sensor with remarkable catalytic activity. The unidimensional structure of CNT fibers displayed efficient conductivity with enhanced mechanical strength, which makes these fibers far superior as compared to other fibrous-like materials. Copper oxide (CuO) nanoparticles were deposited over the surface of CNT fibers by a binder-free facile electrodeposition approach followed by thermal treatment that enhanced the performance of non-enzymatic glucose sensors. Scanning electron microscopy and energy-dispersive X-ray analysis confirmed the successful deposition of CuO nanoparticles over the fiber surface. Amperometric and voltammetric studies of fiber-based microelectrodes (CuO@CNTFs) toward glucose sensing showed an excellent sensitivity of ∼3000 μA/mM cm², a low detection limit of 1.4 μM, and a wide linear range of up to 13 mM. The superior performance of the microelectrode is attributed to the synergistic effect of the electrocatalytic activity of CuO nanoparticles and the excellent conductivity of CNT fibers. A lower charge transfer resistance value obtained via electrochemical impedance spectroscopy (EIS) also demonstrated the superior electrode performance. This work demonstrates a facile approach for developing CNT fiber-based microelectrodes as a promising solution for flexible and disposable non-enzymatic glucose sensors.

Prism-like bimetallic (Ni-Co) alkaline carboxylate-based non-enzymatic sensor capable of exceptionally high catalytic activity towards glucose

In this study, we fabricated a novel non-enzymatic glucose sensor based on prism-like bimetallic alkaline carboxylate (CoNi-MIM). The morphology and structure of CoNi-MIM were carefully investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), powder X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The electrochemical glucose oxidation of the synthesized sensor was then explored by cyclic voltammetry (CV) and chronoamperometry in alkaline medium. It was found that CoNi-MIM is the optimal choice with a remarkably high sensitivity of 5024.4 μA mM^-1 cm^-2, low detection limit of 56.1 nM (S/N = 3), linear response of up to 14.3 mM and excellent selectivity compared to Co-MIM, CoFe-MIM and CoMn-MIM. Furthermore, the as-fabricated sensor demonstrated appreciable practicality for the determination of glucose in real samples. These results indicate that CoNi-MIM holds a good application prospect in non-enzymatic glucose sensing.

Ni-Coated Diamond-like Carbon-Modified TiO2 Nanotube Composite Electrode for Electrocatalytic Glucose Oxidation

In this paper, a Ni and diamond-like carbon (DLC)-modified TiO2 nanotube composite electrode was prepared as a glucose sensor using a combination of an anodizing process, electrodeposition, and magnetron sputtering. The composition and morphology of the electrodes were analyzed by a scanning electron microscope and energy dispersive X-ray detector, and the electrochemical glucose oxidation performance of the electrodes was evaluated by cyclic voltammetry and chronoamperometry. The results show that the Ni-coated DLC-modified TiO2 electrode has better electrocatalytic oxidation performance for glucose than pure TiO2 and electrodeposited Ni on a TiO2 electrode, which can be attributed to the synergistic effect between Ni and carbon. The glucose test results indicate a good linear correlation in a glucose concentration range of 0.99–22.97 mM, with a sensitivity of 1063.78 μA·mM−1·cm−2 and a detection limit of 0.53 μM. The results suggest that the obtained Ni-DLC/TiO2 electrode has great application potential in the field of non-enzymatic glucose sensors.

Bimetallic Nanomaterials-Based Electrochemical Biosensor Platforms for Clinical Applications

Diabetes is a foremost health issue that results in ~4 million deaths every year and ~170 million people suffering globally. Though there is no treatment for diabetes yet, the blood glucose level of diabetic patients should be checked closely to avoid further problems. Screening glucose in blood has become a vital requirement, and thus the fabrication of advanced and sensitive blood sugar detection methodologies for clinical analysis and individual care. Bimetallic nanoparticles (BMNPs) are nanosized structures that are of rising interest in many clinical applications. Although their fabrication shares characteristics with physicochemical methodologies for the synthesis of corresponding mono-metallic counterparts, they can display several interesting new properties and applications as a significance of the synergetic effect between their two components. These applications can be as diverse as clinical diagnostics, anti-bacterial/anti-cancer treatments or biological imaging analyses, and drug delivery. However, the exploitation of BMNPs in such fields has received a small amount of attention predominantly due to the vital lack of understanding and concerns mainly on the usage of other nanostructured materials, such as stability and bio-degradability over extended-time, ability to form clusters, chemical reactivity, and biocompatibility. In this review article, a close look at bimetallic nanomaterial based glucose biosensing approaches is discussed, concentrating on their clinical applications as detection of glucose in various real sample sources, showing substantial development of their features related to corresponding monometallic counterparts and other existing used nanomaterials for clinical applications.

Nanosized CuO encapsulated Ni/Co bimetal Prussian blue with high anti-interference and stability for electrochemical non-enzymatic glucose detection

Non-enzymatic glucose sensors based on metal oxides are receiving remarkable attention owing to their outstanding characteristics of being easy-to use, low cost, and reusability. However, the disadvantage of weak anti-interference associated with poor selectivity significantly restricts their applicability. Herein, we report a two-step in situ fabrication of nanosized CuO encapsulated Ni/Co bimetal Prussian blue (PB) with a typical core-shell structure, which can be efficiently used for non-enzymatic glucose detection, ascribing to the permeability and abundant active sites of out-shelled crystalline porous Ni/Co PB and the high catalytic activity and conductivity of embedded CuO nanoparticles, afforded by their mutual synergistic interactions. The glassy carbon electrode modified with the hybrid of the CuO-encapsulated Ni/Co PB (simplified as the Ni/Co-PB/CuO/GCE electrode) exhibited a high glucose sensitivity of 600 μA mM-1 cm-2 with a low detection limit of 0.69 μM (S/N = 3), a fast response time (less than 3 s), and excellent long-term stability. In addition, the CuO-encapsulated Ni/Co PB showed favorable anti-interference ability in the presence of ascorbic acid (AA), L-lysine (Lys), dopamine (DA), cysteine (Cys), dopamine (DA), and KCl interferences. The reusability and long-term stability, as well as the practicability of the Ni/Co-PB/CuO/GCE sensing electrode verified by testing real serum samples were also investigated, and the experimental results demonstrated the applicability of the core-shell NiCo-PB/CuO based flexible electrochemical sensor for non-enzymatic glucose sensing in practical applications.

Recent Advances in (Bio)Chemical Sensors for Food Safety and Quality Based on Silver Nanomaterials

There is a continuing need for tools and devices which can simplify, quicken and reduce the cost of analyses of food safety and quality. Chemical sensors and biosensors are increasingly being developed for this purpose, reaping from the opportunities provided by nanotechnology. Due to the distinct electrical and optical properties of silver nanoparticles (AgNPs), this material plays a vital role in (bio)sensor development. This review is an analysis of chemical sensors and biosensors based on silver nanoparticles with application in food and beverage matrices. It consists of academic research published from 2015 to 2020. The paper is structured to separately explore the designs of two major (bio)sensor classes: electrochemical (including voltammetric and impedimetric sensors) and optical sensors (including colourimetric and luminescent), with special focus on the type of silver nanomaterial and its role in the sensor system. The review indicates that diverse nanosensors have been developed, capable of detecting analytes such as pesticides, mycotoxins, fertilisers, microorganisms, heavy metals, and various additives with exceptional analytical performance. Current trends in the design of such sensors are highlighted and challenges which need to be overcome in the future are discussed.

Glucose determination behaviour of gold microspheres-electrodeposited carbon cloth flexible electrodes in neutral media

Despite numerous advances in the field of nonenzymatic glucose detection, monitoring glucose in physiological applications is still a challenge and is mostly limited to electrode surface modification. This study proposes a simple method for electrodepositing cotton-like gold microspheres (CGMs) on a carbon cloth (CC) flexible electrode, with the potential for the functional supporting substrate to monitor glucose in a neutral environment. It was demonstrated that the voltammetric response of glucose oxidation increased with increases in glucose concentration in the 3D functional flexible substrate; moreover, the amperometric response of glucose oxidation increased over time. The results indicate that the functional flexible electrode-made of gold microspheres-based carbon cloth with a predefined geometry and pore-architecture network to promote the medium-permeation and synergetic effects between CGMs and CC-can be a suitable platform for measuring glucose variation in environments with neutral pH. This is particularly relevant because the oxygen-containing functional groups on the CC surface increase the dehydrogenation rate of glucose oxidation in neutral phosphate-buffered saline.

Non-enzymatic electrochemical glucose sensing by Cu2O octahedrons: elucidating the protein adsorption signature

Developing an electrochemical biosensor based on Cu₂O octahedrons for rapid, sensitive and highly selective detection of glucose in real samples with an unprecedented analysis of their protein adsorption signature.

An electrochemical platform for the selective detection of azathioprine utilizing a screen-printed carbon electrode modified with manganese oxide/reduced graphene oxide

Scheme representing the electro-reduction of AZT at Mn₂O₃–rGO/SPCE.

Printable 3D Carbon Nanofiber Networks with Embedded Metal Nanocatalysts

Carbon nanofiber (CNF) nanocatalyst hybrids hold great promise in fields such as energy storage, synthetic chemistry, and sensors. Current strategies to generate such hybrids are laborious and utterly incompatible with miniaturization and large-scale production. Instead, this work demonstrates that Ni nanoparticles embedded in three-dimensional (3D) CNFs of any shape and design can be easily prepared using electrospinning, followed by laser carbonization under ambient conditions. Specifically, a solution of nickel acetylacetonate /polyimide is electrospun and subsequently a design is printed via CO₂ laser (Ni-laser-induced carbon nanofiber (LCNFs)). This creates uniformly distributed small Ni nanoparticles (∼8 nm) very tightly adhered to the CNF network. Morphological and performance characteristics can be directly influenced by metal content and lasing power and hence adapted for the desired application. Here, Ni-LCNFs are optimized for nonenzymatic electrochemical sensing of glucose with great sensitivity of 2092 μA mM^-1 cm^-2 and a detection limit down to 0.3 μM. Its selectivity for glucose vs interfering species (ascorbic and uric acid) is essentially governed by the Ni content. Most importantly, this strategy can be adapted to a whole range of metal precursors and hence provide opportunities for such 3D CNF-nanocatalyst hybrids in point-of-care applications where high-performance but also sustainable and low-cost fabrications are of utmost importance.

Significant enhancement in the electrochemical determination of 4-aminophenol from nanoporous gold by decorating with a Pd@CeO2 composite film

An electrode based on Pd@CeO₂ nanocomposite-decorated nanoporous gold on a carbon fiber paper was achieved, which demonstrated excellent performance in 4-aminophenol determination.

Hierarchical core-shell structured Ni3S2/NiMoO4 nanowires: a high-performance and reusable electrochemical sensor for glucose detection

Designing highly active electrode is important for the fabrication of electrochemical sensing platforms, and core-shell nanostructures with large specific surface areas and ease of accessibility are effective probes for the detection of biomolecules. In this work, we report the development of hierarchical core-shell Ni3S2/NiMoO4 nanowires on a nickel foam substrate (Ni-Ni3S2/NiMoO4) as a non-noble metal catalyst electrode for the electrochemical oxidation of glucose in alkaline electrolyte. As an electrochemical sensor for glucose detection, the fabricated hierarchical Ni-Ni3S2/NiMoO4 core-shell nanowires display an enhanced catalytic response, a fast response time of 1 s with a limit of detection (LOD) of 0.055 μM (S/N = 3), and a higher sensitivity of 10.49 μA μM-1 cm-2. Unlike Ni3S2 or NiMoO4 electrodes, the observed superior catalytic activity towards glucose is mainly due to the promotional effect of NiMoO4 nanosheets on the Ni3S2 nanowires, which can increase the large active surface area and generate numerous active sites within and on the surface walls of the nanowire structures. The developed Ni-Ni3S2/NiMoO4 nanowire electrode can selectively detect glucose in the presence of other carbohydrates, such as fructose, sucrose, lactose, maltose, galactose, mannose, and xylose, indicating potential anti-interference properties. The Ni-Ni3S2/NiMoO4 nanowire electrode is highly stable for reuse and its practical application is demonstrated using real blood serum samples. These results demonstrate that hierarchical core-shell Ni3S2/NiMoO4 nanowires show potential for application in the development of low-cost applied glucose sensors.

Surface Engineering of Carbon Fiber Paper toward Exceptionally High-Performance and Stable Electrochemical Nitrite Sensing

In this work, we introduce our recent finding that the carbon fiber paper (CFP) treated by simple air annealing (OCFP) could be used for exceptionally high-performance electrochemical nitrite sensing. The air-annealing process endows the pristine CFP with higher defective edge/plane sites, more oxygen-containing functional groups, higher roughness, and improved wettability. The electrochemical studies show that the OCFP exhibits excellent sensing performance for nitrite, with an ultralow determination limit of 0.1 μM and a detection limit of 0.07 μM, an ultrawide linear determination range of 0.1-3838.5 μM, a fast current response of 1 s, and a high sensitivity of 930.4 μA mM^-1 cm^-2. These performance values are comparable or even superior to those for most reported noble- or transition-metal-based advanced nitrite sensors. Besides, this electrode also presents satisfactory stability, reproducibility, and feasibility of nitrite sensing in food samples. As an ideal monolithic and metal-free catalyst with ultrahigh and stable detection performance, the OCFP has a high potential to be integrated into next-generation electrochemical sensing devices.

A Flexible Portable Glucose Sensor Based on Hierarchical Arrays of Au@Cu(OH)2 Nanograss

Flexible physiological medical devices have gradually spread to the lives of people, especially the elderly. Here, a flexible integrated sensor based on Au nanoparticle modified copper hydroxide nanograss arrays on flexible carbon fiber cloth (Au@Cu(OH)2/CFC) is fabricated by a facile electrochemical method. The sensor possesses ultrahigh sensitivity of 7.35 mA mM-1 cm-2 in the linear concentration range of 0.10 to 3.30 mM and an ultralow detection limit down to 26.97 nM. The fantastic sensing properties can be ascribed to the collective effect of the superior electrochemical catalytic activity of nanograss arrays with dramatically enhanced electrochemically active surface area as well as mass transfer ability when modified with Au and intimate contact between the active material (Au@Cu(OH)2) and current collector (CFC), concurrently supplying good conductivity for electron/ion transport during glucose biosensing. Furthermore, the device also exhibits excellent anti-interference and stability for glucose detection. Owing to the distinguished performances, the novel sensor shows extreme reliability for practical glucose testing in human serum and juice samples. Significantly, these unique properties and the soft structure of silk fabric can provide a promising structure design for a flexible micro-device and a great potential material candidate of electrochemical glucose sensor.

A Simple Electrochemical Route to Access Amorphous Co-Ni Hydroxide for Non-enzymatic Glucose Sensing

Among the numerous transition metal hydroxide materials, cobalt- and nickel-based hydroxides have been extensively studied for their excellent electrochemical performances such as non-enzymatic electrochemical sensors. Binary cobalt-nickel hydroxide has received extensive attention for its exceptionally splendid electrochemical behaviors as a promising glucose sensor material. In this work, we report the synthesis of three-dimensional amorphous Co-Ni hydroxide nanostructures with homogeneous distribution of elements via a simple and chemically clean electrochemical deposition method. The amorphous Co-Ni hydroxide, as a non-enzymatic glucose sensor material, exhibits a superior biosensing performance toward glucose detection for its superior electron transfer capability, high specific surface area, and abundant intrinsic redox couples of Ni2+/Ni3+ and Co2+/Co3+/Co4+ ions. The as-synthesized amorphous Co-Ni hydroxide holds great potential in glucose monitoring and detection as non-enzymatic glucose sensors with high sensitivity 1911.5 μA mM-1 cm-2 at low concentration, wide linear range of 0.00025-1 mM and 1-5 mM, low detection limit of 0.127 μM, super long-term stability, and excellent selectivity in 0.5 M NaOH solution.

Synthesis of wearable and flexible NiP0.1-SnOx/PANI/CuO/cotton towards a non-enzymatic glucose sensor

Ni-SnO_x, PANI and CuO nanoparticles were synthesized on cotton fabric through chemical methods to make a new flexible high-performance non-enzymatic glucose sensor. FESEM, XRD, XPS, EDS and ATR analysis were employed to characterize the structure and the morphology of the nanomaterials. The high electrochemical performance of nickel and copper oxide and hydroxide on a conductive template leads to fabrication of a wearable and flexible cotton electrode with an excellent electrocatalytic activity to oxidize glucose. This hybrid system on the fabric as an electrode indicates a detection limit of 130 nM with wide linear range of 0.001-10 mM. The sensitivity was measured to be 1625 and 1325 μA mM^-1 cm^-2 for the ranges of 0.001-1 and 1-10 mM, respectively. Long-term stability, appropriate selectivity and reusability for many times make possibility for utilizing the fabricated sensor in the practical applications. The fabric is a wide linear range electrode with low detection limit to sense glucose concentration in the body fluids as well as the human blood that can be presumably suggested for designing other similar flexible types of sensor.

Cobalt Oxide Porous Nanocubes-Based Electrochemical Immunobiosensing of Hepatitis B Virus DNA in Blood Serum and Urine Samples

In this work, we report a new biosensing platform for hepatitis B virus (HBV) DNA genosensing using cobalt oxide (Co₃O₄) nanostructures. The tunable morphologies of Co₃O₄ nanostructures such as porous nanocubes (PNCs), nanooctahedra (NOHs), and nanosticks (NSKs) are synthesized, and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) patterns, nitrogen adsorption/desorption isotherms (BET), and electrochemical impedance spectral (EIS) methods. The HBV probe DNA (ssDNA) is immobilized on the Co₃O₄ nanostructures through coordinate bond formation between nucleic acid of ssDNA and Co metal, which results in highly stable nanostructured biosensing platform. To the best of our knowledge, first time the target cDNA of HBV is detected using ssDNA/Co₃O₄PNCs/GCE electrode by EIS method with a limit of detection (LOD) of 0.38 pM (signal-to-noise ratio (S/N) = 3). Moreover, the ssDNA/Co₃O₄PNCs/GCE has shown excellent specificity to HBV target cDNA, compared with noncomplementary DNA, and 1- and 3-mismatch DNAs. Finally, we explore ssDNA/Co₃O₄PNCs/GCE as potential electrode to test HBV DNA in blood serum and urine samples for practical applications.

Three-dimensional flower-like Ni–Mn–S on Ti mesh: a monolithic electrochemical platform for detecting glucose

Three-dimensional flower-like Ni–Mn–S on Ti mesh as a monolithic electrochemical platform was constructed and exhibited satisfactory glucose sensing performance.

Ni–Fe hybrid nanocubes: an efficient electrocatalyst for non-enzymatic glucose sensing with a wide detection range

A sensor for the determination of glucose is developed based on Ni–Fe hybrid nanocubes, which exhibit excellent sensing performance.

Cobalt Phosphate Nanostructures for Non-Enzymatic Glucose Sensing at Physiological pH

Nanostructured materials have potential as platforms for analytical assays and catalytic reactions. Herein, we report the synthesis of electrocatalytically active cobalt phosphate nanostructures (CPNs) using a simple, low-cost, and scalable preparation method. The electrocatalytic properties of CPNs toward the electrooxidation of glucose (Glu) were studied by cyclic voltammetry and chronoamperometry in relevant biological electrolytes, such as phosphate-buffered saline (PBS), at physiological pH (7.4). Using CPNs, Glu detection could be achieved over a wide range of biologically relevant concentrations, from 1 to 30 mM Glu in PBS, with a sensitivity of 7.90 nA/mM cm² and a limit of detection of 0.3 mM, thus fulfilling the necessary requirements for human blood Glu detection. In addition, CPNs showed a high structural and functional stability over time at physiological pH. The CPN-coated electrodes could also be used for Glu detection in the presence of interfering agents (e.g., ascorbic acid and dopamine) and in human serum. Density functional theory calculations were performed to evaluate the interaction of Glu with different faceted cobalt phosphate surfaces; the results revealed that specific surface presentations of under-coordinated cobalt led to the strongest interaction with Glu, suggesting that enhanced detection of Glu by CPNs can be achieved by lowering the surface coordination of cobalt. Our results highlight the potential use of phosphate-based nanostructures as catalysts for electrochemical sensing of biochemical analytes.

Microwave-assisted synthesis of Pd3Ag nanocomposite via nature polysaccharide applied to glucose detection

In this work, a green strategy is performed to fabricate Pd₃Ag nanoparticles (NPs) using plant-extracted polysaccharide (Lilium brownie polysaccharide, LBP). As-obtained Pd₃Ag nanocomposite (Pd₃Ag-LBP/C) is surveyed including transmission election microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and powder X-ray diffraction (XRD). The result of glucose detection application shows that the Pd₃Ag-LBP/C glassy carbon electrode (GCE) exhibits good stability and sensitivity. It can completely cover the normal blood glucose concentration (3-8 mM) with high sensitivity of 77.20 μA mM^-1 cm^-2. This work undoubtedly has positive effects on green synthesis development. It not only proves the practicability of building nanomaterials by polysaccharide, but also offers an environmentally friendly way for fabricating other nanomaterials.

Retracted Article: Anomalies in growth of electrodeposited Ni–Fe nanogranular films

Thin Ni–Fe films were produced via electrodeposition onto silicon substrates using direct current and pulse current (with different pulse durations) regimes.

Synthesis of nickel(ii) coordination polymers and conversion into porous NiO nanorods with excellent electrocatalytic performance for glucose detection

Porous NiO nanostructures are fabricated by calcinating the Ni(SA)₂(H₂O)₄coordination polymers and used as electrocatalysts for the detection of glucose in a nonenzymatic electrochemical sensor.

Multifunctional porous NiCo2O4 nanorods: sensitive enzymeless glucose detection and supercapacitor properties with impedance spectroscopic investigations

Multifunctional NiCo₂O₄ nanorods fabricated by a simple two-step method exhibit excellent performance in glucose sensors as well as supercapacitors.

Highly active 3-dimensional cobalt oxide nanostructures on the flexible carbon substrates for enzymeless glucose sensing

3-Dimensional cobalt oxide nanostructures on the flexible carbon substrates for enzymeless glucose sensing.

Fabrication of 3 D Mesoporous Black TiO2 /MoS2 /TiO2 Nanosheets for Visible-Light-Driven Photocatalysis

A novel 3 D mesoporous black TiO2 (MBT)/MoS2 /MBT sandwich-like nanosheet was successfully fabricated using a facile mechanochemical process combined with an in situ solid-state chemical reduction approach, followed by mild calcination (350 °C) under an argon atmosphere. The MBT/MoS2 /MBT exhibits a 3 D sandwich-like nanosheet structure and heterojunctions are formed at the interfaces between MoS2 and black TiO2 . The significantly narrowed band gap of MBT/MoS2 /MBT is attributed to the introduction of MoS2 and the formed Ti(3+) species in the frameworks. The visible-light photocatalytic degradation rate of methyl orange and the hydrogen production rate are as high as 89.86 % and 0.56 mmol h(-1)  g(-1) , respectively. The introduction of MoS2 and Ti(3+) in the frameworks favors the visible-light absorption and the separation of photogenerated charges, and the 3 D sandwich-like heterojunction structure facilitates the transfer of photogenerated charges.

NiCo alloy nanoparticles anchored on polypyrrole/reduced graphene oxide nanocomposites for nonenzymatic glucose sensing

The combination of PPy and graphene oxide was used as an effective supporting substrate for the loading of alloys.