A novel non-enzymatic glucose sensor based on Pt3Ru1 alloy nanoparticles with high density of surface defects

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.

Manganese Carbonate/Laser-Induced Graphene Composite for Glucose Sensing

Laser-induced graphene (LIG) has received great interest as a potential candidate for electronic and sensing applications. In the present study, we report the enhanced performance of a manganese carbonate-decorated LIG (MnCO3/LIG) composite electrode material employed for electrochemical glucose detection. Initially, the porous LIG was fabricated by directly lasing poly(ether sulfone) membrane substrate. Then, the MnCO3/LIG composite was synthesized via a hydrothermal method. Later, MnCO3/LIG was immobilized onto a glassy carbon electrode surface and employed for glucose detection. The structure of the MnCO3/LIG composite was carefully characterized. The influence of the MnCO3/LIG composite on the performance of the electrode was investigated using cyclic voltammetry curves. The MnCO3/LIG composite exhibited an excellent sensitivity of 2731.2 μA mM-1 cm-2, and a limit of detection of 2.2 μM was obtained for the detection of glucose. Overall, the performance of the MnCO3/LIG composite was found to be superior to that of most of the MnCO3-based composites.

Facile synthesis of a CuSe/PVP nanocomposite for ultrasensitive non-enzymatic glucose biosensing

Non-enzymatic glucose biosensors show high sensitivity, lower response time, wide linear range and low cost. Copper based composites show excellent electrocatalytic tunability and lead to a better charge transfer in electrochemical non-enzymatic glucose biosensors. In this work, a nanocomposite of polyvinylpyrrolidone (PVP) and copper selenide was synthesized by a facile one pot sol gel method. Synthesized nanomaterials were characterized by XRD, FTIR, UV-visible spectroscopy, SEM, EDS and XPS techniques. Electrochemical behavior was analyzed by cyclic voltammetry (CV), electrochemical impendence (EIS) and chronoamperometry techniques. XRD analysis revealed a hexagonal structure and crystalline nature of CuSe/PVP. FTIR spectra depicted C-N bonding at 1284 cm-1 and C[double bond, length as m-dash]O stretching at 1634 cm-1, which indicated the presence of PVP in the nanocomposite. Stretching at 823 cm-1 was attributed to the presence of copper selenide. UV-visible absorption indicated the bandgap of copper selenide/PVP at 2.7 eV. SEM analysis revealed a flake like morphology of CuSe/PVP. EDS and XPS analysis confirmed the presence of copper and selenium in the prepared nanocomposite. Prior to employing for biosensing applications, it is important to evaluate the antibacterial activity of nanomaterials for long term use in biological in vitro testing. These materials have shown an efficient inhibition zone of 26 mm against Gram negative Pseudomonas at 50 μg ml-1 and MIC value of 10 μg ml-1. Cyclic voltammetry shows that CuSe/PVP is a promising biosensor for monitoring glucose levels in a wide linear range of 0.5 mM to 3 mM at an excellent sensitivity of 13 450 μA mM-1 cm-2 with an LOD of 0.223 μM. Chronoamperometry measurements revealed a selective behavior of CuSe/PVP for glucose biosensing amongst ascorbic acid and dopamine as common interfering molecules. The nanocomposite was stable after 8 repeated cycles with 92% retention for glucose sensing capacity. This is attributed to the stable nature of the CuSe/PVP nanocomposite as well as higher surface area of available active sites. Herein the CuSe/PVP nanocomposite offered reasonable selectivity, high sensitivity wide linear range with very low LOD, as well as being abundant in nature, this Cu based biosensor has promising applications for future point of care tests (POCT).

Controlled synthesis of Cu-Sn alloy nanosheet arrays on carbon fiber paper for self-supported nonenzymatic glucose sensing

Nanoalloy shows significant advantages and broad application prospects in chemical catalysis, due to the possessed high specific surface energy and abundant active sites can greatly promote their catalytic performance. In this work, morphology-controlled Cu-Sn alloy nanosheet arrays supported on carbon fiber paper (CP) substrate (Cu-Sn/CP) have been developed by a facile one-step electrodeposition technique at room temperature for the first time. Benefiting from the large active surface area, considerable ion transport channels and strong synergistic catalytic effect between Cu and Sn, the as-prepared Cu-Sn/CP served as a self-supported electrode for efficient nonenzymatic glucose sensing. Under optimized conditions, Cu-Sn/CP electrode offers wide linear ranges of 0.0005-2.0 mM and 2.0-10.0 mM, respectively. The detection limit is as low as 0.061 μM (S/N = 3). Cu-Sn/CP electrode also exhibited excellent selectivity and stability. Additionally, the proposed sensor is proven to be suitable for the detection of glucose in human serum samples.

A flexible Ni–Ag-coated nylon yarn as an electrode for non-enzymatic glucose sensing

SCNY@Ni was prepared by electrochemical deposition and exhibited excellent performance for glucose determination.

Applications of Advanced Materials for Non-Enzymatic Glucose Monitoring: From Invasive to the Wearable Device

Diabetes mellitus (DM) is a global health problem leading to many complications and disabilities in life adjusting activities and even dead. Monitoring glucose levels is a key factor in diagnosis and management of DM. Conventional glucose sensors consisted of immobilized enzymes, are so susceptible to environmental conditions. In this way, nonenzymatic biosensors have attracted extensive attentions in many clinical diagnostics applications. To date, the finger pricking test is a common enzyme-based glucometer that is an invasive and inconvenient and may lead to infections in the injection sites. So, working on the possibility of cutaneous or subcutaneous insertion of devices as a noninvasive or minimally-invasive systems for continuous glucose controlling approaches through human biofluids (blood, perspiration, tears, saliva, etc.) have stimulated growing interest. This review summarizes recent nonenzymatic and noninvasive biofluids glucose monitoring systems which are highly resilience and stretchable to continuously adapt to body movements during common physical activity. Sensors are based on their constituent materials including carbon-based, metal nanoparticles, polymer, and hydrogel systems are classified for electrochemical, and optical glucose detection. Finally, we address the drawbacks and challenges of enzyme-free sensors which are aroused sustaining research passion to be used in point-of-care medical diagnostics applications.

Engineering of Electron Affinity and Interfacial Charge Transfer of Graphene for Self-Powered Nonenzymatic Biosensor Applications

Facile electron transport and intimate electronic contact at the catalyst-electrode interface are critical for the ideal performance of electrochemical devices such as glucose biofuel cells and biosensors. Here, through a comprehensive experimental-theoretical exploration, we demonstrate that engineering of interfacial properties, including interfacial electron dynamics, electron affinity, electrode-catalyst-adsorbate electrical synergy, and electrocatalytically active surface area, can lead to highly efficient graphene-based electrochemical devices. We selected two closely related but electronically and surface chemically different functionalized graphene analogues-graphene acid (GA) and reduced graphene oxide (rGO)-as the model graphenic platforms. Our studies reveal that compared to rGO, GA is a superior bifunctional catalyst with high oxygen reduction reaction (an onset potential of 0.8 V) and good glucose oxidation activities. Spectroscopic and electrochemical analysis of GA and rGO indicated that the higher carboxylic acid content on GA increases its overall electron affinity and coupled with improved conductivity and band alignment, which leads to GA's better electrochemical performance. The formulation of a heterostructure between GA and samarium oxide (Sm₂O₃) nanoparticles led to augmented conductivity (lower charge-transfer resistance) and glucose binding affinity, resulting in a further enhanced glucose oxidation activity. The interdimensional Sm₂O₃/GA heterostructure, leveraging their enhanced glucose oxidation capacity, exhibited excellent nonenzymatic amperometric glucose sensing performance, with a detection limit of 107 nM and a sensitivity of 20.8 μA/μM. Further, a nonenzymatic, membrane-free glucose biofuel cell (with Sm₂O₃/GA heterostructure as anode and GA as biocathode) produced a power density of 3.2 μW·cm^-2 (in PBS spiked with 3 mM glucose), which can function as self-powered glucose sensors with 70 nM limit of detection. The study establishes the potential of interfacial engineering of GA to engage it as a highly tunable substrate for a broad range of electrochemical applications, especially in future self-powered biosensors.

Developments of the Electroactive Materials for Non-Enzymatic Glucose Sensing and Their Mechanisms

A comprehensive review of the electroactive materials for non-enzymatic glucose sensing and sensing devices has been performed in this work. A general introduction for glucose sensing, a facile electrochemical technique for glucose detection, and explanations of fundamental mechanisms for the electro-oxidation of glucose via the electrochemical technique are conducted. The glucose sensing materials are classified into five major systems: (1) mono-metallic materials, (2) bi-metallic materials, (3) metallic-oxide compounds, (4) metallic-hydroxide materials, and (5) metal-metal derivatives. The performances of various systems within this decade have been compared and explained in terms of sensitivity, linear regime, the limit of detection (LOD), and detection potentials. Some promising materials and practicable methodologies for the further developments of glucose sensors have been proposed. Firstly, the atomic deposition of alloys is expected to enhance the selectivity, which is considered to be lacking in non-enzymatic glucose sensing. Secondly, by using the modification of the hydrophilicity of the metallic-oxides, a promoted current response from the electro-oxidation of glucose is expected. Lastly, by taking the advantage of the redistribution phenomenon of the oxide particles, the usage of the noble metals is foreseen to be reduced.

A novel non-enzymatic glucose sensor based on NiFe(NPs)-polyaniline hybrid materials

This article was focused on the elaboration of NiFe-Polyaniline glucose sensors via electrochemical technique. Firstly, the PANi (polyaniline) fibers were synthesized by oxidation of the monomer aniline on FTO (fluorine tin oxide) substrate. Secondly, the Nickel-Iron nanoparticles (NiFe (NPs)) were obtained by the Chronoamperometry method on the Polyaniline surface. The NiFe-PANi hybrid electrode was characterized by scanning electron microscopy (SEM), force atomic microscopy (AFM), Fourier-transformed infrared (FTIR), and X-ray diffraction (XRD). The electrochemical glucose sensing performance of the NiFe alloy nanoparticle was studied by cyclic voltammetry and amperometry. The fabricated glucose sensor Ni-Fe hybrid material exhibited many remarkable sensing performances, such as low-response time (4 s), sensitivity (1050 μA mM^-1 cm^-2), broad linear range (from 10 μM -1 mM), and low limit of detection (LOD) (0.5 μM, S/N = 3). The selectivity, reliability, and stability of the NiFe hybrid material for glucose oxidation were also investigated. All the results demonstrated that the NiFe-PANi/FTO hybrid electrode is very promising for application in electrochemical glucose sensing.

Boric acid modified S and N co-doped graphene quantum dots as simple and inexpensive turn-on fluorescent nanosensor for quantification of glucose

A new fluorescent nanosensor based on S and N co-doped graphene quantum dots (S,N-GQDs) modified by boric acid was designed for glucose detection. First, the S,N-GQDs was prepared via one pot hydrothermal process utilizing citric acid and thiourea as precursors. Then, S,N-GQDs was modified by boric acid to fabricate (B)/S,N-GQDs. The excitation dependent photoluminescence spectra of (B)/S,N-GQDs confirmed the heteroatom (S,N) dopant effect on GQDs emission. FT-IR and energy dispersive X-ray (EDX) spectroscopies confirmed the modification of S,N-GQDs with boric acid. The optical and electrochemical band gaps of the obtained (B)/S,N-GQDs were found to be 2.7 and 2.5 eV, respectively. The boric acid functionalized S,N-GQDs exhibited fluorescent enhancement at 455 nm upon addition of glucose. Such fluorescence response was used for glucose quantification with a detection limit of 5.5 μM which is comparable with previous boronic acid based fluorescent sensing systems. However, compared with earlier reported expensive boronic acid based glucose sensors, this modified system is simpler, more economical, and efficient. A mechanism was proposed for fluorescence enhancement based on the reaction of cis-diol units of glucose with the boric acid groups of (B)/S,N-GQDs which creates rigid (B)/S,N-GQDs-glucose structures, restricting the non-radiative intramolecular motions and results in the fluorescent enhancement.

Development of an electrochemical enzyme-free glucose sensor based on self-assembled Pt-Pd bimetallic nanosuperlattices

The huge demand for the clinical diagnosis of diabetes mellitus has prompted the development of great-performance sensing platforms for glucose detection. Non-enzymatic glucose sensors are getting closer to their use in realistic applications. In this work, polyvinylpyrrolidone (PVP)-conjugated bimetallic Pt-Pd nanosuperlattices were synthesized precisely through a simple synthesis procedure, leading to controllable spherical morphologies with significantly fine and precise nanostructures in a size range of ∼3-5 nm by the reduction of Pt and Pd precursors in ethylene glycol, using an ultrasonic method. High-resolution transmission electron microscopy (HRTEM) measurements evidenced the formation of Pt-Pd bimetallic nanosuperlattices (BMNSLs). The superlattice-fringe patterns (111) of bimetallic Pt-Pd NSLs were identified in the HRTEM images, clearly showing their crystalline nature. The prepared material was used in the electrochemical oxidation of glucose using voltammetry analyses. The experimental evidence indicates that the Pt-Pd BMNSL modified glassy carbon electrode is effective for the selective amperometric detection of glucose in the presence of galactose, sucrose, fructose, lactose, and ascorbic acid. Moreover, its application in the detection of glucose in real serum and urine samples was assessed and good recoveries are achieved. The results show that a Pt-Pd bimetallic nanosuperlattice with high surface area, catalytic activity, and superior selectivity could be a promising material in the generation of novel electrodes for low-cost non-enzymatic glucose sensors.

Porous Platinum Black-Coated Minimally Invasive Microneedles for Non-Enzymatic Continuous Glucose Monitoring in Interstitial Fluid

Individuals with diabetes can benefit considerably from continuous blood glucose monitoring. To address this challenge, a proof-of-concept was performed for continuous glucose monitoring (CGM) based on an enzymeless porous nanomaterial (pNM)-modified microneedle electrode array (MNEA). The pNM sensing layer was electrochemically deposited on MNs by applying a fixed negative current of -2.5 mA cm^-2 for 400 s. The pNM-modified MNEA was packed using a biocompatible Nafion ionomer. The fabricated MNEAs were 600 × 100 × 150 µm in height, width, and thickness, respectively. The surfaces of the modified MNs were characterized by scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The fabricated MNEAs showed a wide dynamic range (1-30 mM) in phosphate-buffered saline (PBS) and in artificial interstitial fluid (ISF), with good sensitivities (PBS: 1.792 ± 0.25 µA mM^-1 cm^-2, ISF: 0.957 ± 0.14 µA mM^-1 cm^-2) and low detection limits (PBS: 7.2 µM, ISF: 22 µM). The sensor also showed high stability (loss of 3.5% at the end of 16 days), selectivity, and reproducibility (Relative standard deviations (RSD) of 1.64% and 0.70% for intra- and inter-assay, respectively) and a good response time (2 s) with great glucose recovery rates in ISF (98.7-102%).

Facile synthesis of CuCo2O4@NiCo2O4 hybrid nanowire arrays on carbon cloth for a multicomponent non-enzymatic glucose sensor

The design of hierarchical heterogeneous structures with rational components is considered as a promising method to enhance the properties of electrocatalyst. Binary metal oxides, with high electrochemical activity, have attracted considerable interest in glucose determination. In this work, we synthesized the CuCo₂O₄@NiCo₂O₄ hybrid structure on conductive carbon cloth (CC) via a simple two-step hydrothermal process and investigated its catalytic ability toward glucose. The two individual components that make up this hybrid electrode have good electrical conductivity and excellent catalytic properties for glucose, so the smart combination of these two active materials can provide more catalytic sites and sufficient redox couples for the glucose oxidation. As a result, the CuCo₂O₄@NiCo₂O₄ modified CC presented superior glucose sensing properties, including ultrahigh sensitivity, fast response time, wide linear range and acceptable detection limit. Besides, the sample also exhibited good selectivity for substances in human blood that interfere with glucose detection, such as UA, AA, fructose, sucrose and KCl. The potential of the CuCo₂O₄@NiCo₂O₄/CC electrode for practical application was investigated by measuring the glucose concentration in real serum samples. These results prove that the construction of hierarchical ordered structure is conducive to the improvement of glucose sensor.

Non-enzymatic sensor for determination of glucose based on PtNi nanoparticles decorated graphene

Diabetes has become a universal epidemic in recent years. Herein, the monitoring of glucose in blood is of importance in clinical applications. In this work, PtNi alloy nanoparticles homogeneously dispersed on graphene (PtNi alloy-graphene) was synthesized as a highly effective electrode material for glucose detection. Based on the modified PtNi alloy-graphene/glass carbon (PtNi alloy-graphene/GC) electrode, it is found that the PtNi alloy-graphene/GC electrode exhibited excellent electrocatalytic performance on glucose oxidation. Furthermore, the results from amperometric current–time curve show a good linear range of 0.5–15 mM with the limit of detection of 16 uM (S/N = 3) and a high sensitivity of 24.03 uAmM⁻¹ cm⁻². On account of the good selectivity and durability, the modified electrode was successfully applied on glucose detection in blood serum samples.

N,N-dicarboxymethyl Perylene-diimide modified CeCoO3: Enhanced peroxidase activity, synergetic catalytic mechanism and glutathione colorimetric sensing

N,N-dicarboxymethyl Perylene-diimide (PDI) modified CeCoO₃ nanocomposites were prepared by a two-step method. After modification with PDI molecules, the obtained PDI-CeCoO₃ nanocomposites were demonstrated to possess the heightened peroxidase-like activity, compared with that of pure CeCoO₃ nanoparticles. In the presence of H₂O₂, the heightened peroxidase-like behaviors of PDI-CeCoO₃ were evaluated by the oxidation of the colorless substrate 3,3,5,5-tetramethylbenzidine (TMB) into blue oxTMB, which was detected visually only in 4 min. Importantly, a systematic study of catalytic activity of PDI-CeCoO₃ by different means, including fluorescent probe, electrochemical data, diffuse reflection spectra together with free radical scavenger is executed, verifying that the catalytic activity were from O₂^- and electron holes (h⁺). And, the transfer of photogenerated carriers in the PDI-CeCoO₃ was the Z-scheme heterojuntion mechanism. Furthermore, the peroxidase-like activity of PDI-CeCoO₃ was significantly inhibited by Glutathione (GSH), resulting in fading of blue oxTMB. Based on this, a colorimetric assay for GSH biosensing has been developed. And, the liner range for GSH detection is from 1 to 10 μM with a detection limit of 0.658 μM. The recovery of GSH with different concentrations from 90.0% to 105.9% and the relative standard deviation (RSD) from 1.9% to 5.1%. This colorimetric sensor can be used to detect GSH in real samples.

Insightful Analysis of Phenomena Arising at the Metal|Polymer Interphase of Au-Ti Based Non-Enzymatic Glucose Sensitive Electrodes Covered by Nafion

This paper focuses on the examination of glucose oxidation processes at an electrode material composed of gold nanoparticles embedded in a titanium template. Three different conditions were investigated: the chloride content in the electrolyte, its ionic conductivity and the presence of a Nafion coating. The impact of the provided environment on the oxidation reaction was evaluated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Two models, namely: chemisorption and incipient hydrous oxide/adatom mediator (IHOAM), were applied to explain the complex voltammetric responses of the electrodes exposed to solutions of varied glucose concentrations. Three different phenomena were observed for the studied cases. The first is related to the transition between the dominant mechanism of glucose oxidation from the IHOAM model to the chemisorption model. This happens only in an electrolyte containing chlorides after exceeding a certain amount of glucose. The second effect exhibits a bottleneck nature resulting from the presence of Nafion on the electrode’s surface. In this case, mass transport through the semi-permeable polymer is hampered, due to the blocking of channels and physical internal cross-linking. This leads to a preconcentration of glucose inside the pores resulting in an increase in both the material sensitivity and the linear range of the calibration curve. Lastly, the third effect is manifested in a low concentration of the supporting electrolyte. It is based on the fact that mass transport of hydroxyl ions is governed not only by diffusion, but also by migration. These three effects have a tremendous impact on the glucose oxidation mechanism and reveal its very complex nature.

Recent advances of electrochemical and optical enzyme-free glucose sensors operating at physiological conditions

Diabetes is a pathological condition that requires the continuous monitoring of glucose level in the blood. Its control has been tremendously improved by the application of point-of-care devices. Conventional enzyme-based sensors with electrochemical and optical transduction systems can successfully measure the glucose concentration in human blood, but they suffer from the low stability of the enzyme. Non-enzymatic wearable electrochemical and optical sensors, with low-cost, high stability, point-of-care testing and online monitoring of glucose levels in biological fluids, have recently been developed and can help to manage and control diabetes worldwide. Advances in nanoscience and nanotechnology have enabled the development of novel nanomaterials that can be implemented for the use in enzyme-free systems to detect glucose. This review summarizes recent developments of enzyme-free electrochemical and optical glucose sensors, as well as their respective wearable and commercially available devices, capable of detecting glucose at physiological pH conditions without the need to pretreat the biological fluids. Additionally, the evolution of electrochemical glucose sensor technology and a couple of widely used optical detection systems along with the glucose detection mechanism is also discussed. Finally, this review addresses limitations and challenges of current non-enzymatic electrochemical, optical, and wearable glucose sensor technologies and highlights opportunities for future research directions.

Controlled synthesis of flower-like cobalt phosphate microsheet arrays supported on Ni foam as a highly efficient 3D integrated anode for non-enzymatic glucose sensing

CoPO MA/NF was synthesized in a controlled way and utilized as an efficient 3D integrated electrode for enzyme-free glucose sensing.

Nonenzymatic Glucose Sensing and Magnetic Property Based On the Composite Formed by Encapsulating Ag Nanoparticles in Cluster-Based Co-MOF

Utilizing the oxygen-bridged 5,5'-oxidiisophthalic acid (H₄L) linker, one Co(II)-based 3D porous MOF {[Co₅(L)₂(OH)₂(OH₂)₂(H₂O)₄]·2DMF·H₂O}_n (1) with pentanuclear [Co₅(μ₃-OH)₂(μ₂-OH₂)₂]⁸⁺ cluster was prepared. The glassy carbon electrode was modified by 1, and the obtained electrode revealed electrocatalytic performance for glucose oxidation. The porous MOF matrix is beneficial for dispersing Ag nanoparticles evenly in the interior cages or channels, so Ag@1 composite composed of both Ag nanoparticles and MOF was further prepared through deposition-reduction method to enhance electrocatalytic activity. The result demonstrates that the glucose oxidation by Ag@1 was greatly increased with low detection limit (1.32 μM) and good selectivity and sensitivity (0.135 μA μM^-1), which promote the application of MOF-template porous composites as advanced electrochemical sensor materials. Furthermore, 1 shows an interesting magnetic spin-glass slow dynamics for the existing of peculiar pentanuclear Co(II) clusters.

A non-enzymatic amperometric glucose sensor based on the use of graphene frameworks-promoted ultrafine platinum nanoparticles

Ultrafine platinum nanoparticles are grown on a 3D graphene framework (GF-Pt) via a hydrothermal method. The material, when placed on a glassy carbon electrode (GCE), displays enhanced electrocatalytic activity towards glucose oxidation. This is assumed to be the result of the numerous easily accessible active sites, an enlarged electrochemically active area, and the presence of multiple electron/ion transport channels. The modified GCE can be operated at a low potential (- 0.15 V vs. Ag/AgCl) has linear responses in the 0.1 μM - 0.01 mM and 0.01 mM - 20 mM glucose concentration range, and a 30 nM detection limit. It was applied to the rapid determination of glucose in human serum samples. Graphical abstract Schematic presentation of a glassy carbon electrode modified with ultrafine Pt nanoparticles grown on a graphene framework (GFs-Pt). GFs-Pt presents enhanced electrocatalytic activity towards glucose oxidation. GFs-Pt is used in a sensitive non-enzymatic amperometric glucose sensor.

A NiFe Alloy Reduced on Graphene Oxide for Electrochemical Nonenzymatic Glucose Sensing

A NiFe alloy nanoparticle/graphene oxide hybrid (NiFe/GO) was prepared for electrochemical glucose sensing. The as-prepared NiFe/GO hybrid was characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD). The results indicated that NiFe alloy nanoparticles can be successfully deposited on GO. The electrochemical glucose sensing performance of the as-prepared NiFe/GO hybrid was studied by cyclic voltammetry and amperometric measurement. Results showed that the NiFe/GO-modified glassy carbon electrode had sensitivity of 173 μA mM⁻¹ cm⁻² for glucose sensing with a linear range up to 5 mM, which is superior to that of commonly used Ni nanoparticles. Furthermore, high selectivity for glucose detection could be achieved by the NiFe/GO hybrid. All the results demonstrated that the NiFe/GO hybrid has promise for application in electrochemical glucose sensing.

Recent advances in electrochemical non-enzymatic glucose sensors - A review

This review encompasses the mechanisms of electrochemical glucose detection and recent advances in non-enzymatic glucose sensors based on a variety of materials ranging from platinum, gold, metal alloys/adatom, non-precious transition metal/metal oxides to glucose-specific organic materials. It shows that the discovery of new materials based on unique nanostructures have not only provided the detailed insight into non-enzymatic glucose oxidation, but also demonstrated the possibility of direct detection in whole blood or interstitial fluids. We critically evaluate various aspects of non-enzymatic electrochemical glucose sensors in terms of significance as well as performance. Beyond laboratory tests, the prospect of commercialization of non-enzymatic glucose sensors is discussed.