Non-enzymatic Electrochemical Glucose Sensor Research Articles

A Wearable Electrochemical Sensor Based on Single-Atom Pt Anchored on Activated NiCo-LDH/Ti3C2Tx for Real-Time Monitoring of Glucose.

Wearable, noninvasive sweat sensors enable real-time monitoring of metabolites in human health management. However, the commercial enzyme-based and currently nonenzymatic glucose sensor represents sluggish glucose oxidation kinetics and a narrow sensing range. Rational design of sensitive materials is significant yet faces a huge challenge. Herein, we construct a single-atom Pt supported on NiCo-LDH/Ti3C2Tx heterostructures (Pt1-NiCo-LDH/Ti3C2Tx) as the nonenzymatic electrochemical glucose sensor sensitive materials for selective detection of glucose level in human sweat. The obtained Pt1-NiCo-LDH/Ti3C2Tx with improved structural stability and enhanced charge transfer efficiency shows a low oxidation peak potential of 0.49 V, high sensitivity of 506.6 μA mM-1 cm-2, a low detection limit of 0.035 μM, and long-term stability toward the glucose detection. The wearable sensor, coupled with a wireless transmission module and a signal processing chip, is used for real-time perspiration glucose monitoring during outdoor exercise. The result is comparable to that of high-performance liquid chromatography (HPLC). This research provides a new paradigm for designing a wearable nonenzymatic electrochemical glucose sensor, enabling noninvasive real-time monitoring of glucose concentrations in human sweat.

ZnFe(PBA)@Ti3C2Tx nanohybrid-based highly sensitive non-enzymatic electrochemical sensor for the detection of glucose in human sweat

The ZnFe prussian blue analogue [ZnFe(PBA)] was infused with Ti3C2Tx (MXene) denoted as ZnFe(PBA)@Ti3C2Tx and was prepared by an in-situ sonication method to use as a non-enzymatic screen printed electrode sensor. The advantage of non-enzymatic sensors is their excellent sensitivity, rapid detection, low cost and simple design. The synthesized ZnFe(PBA)@Ti3C2Tx was characterized for its physical and chemical characterization by XRD, Raman, XPS, EDAX, and FESEM analysis. It possessed multiple functionalized layers and a cubic structure in the nanohybrid. Further, the sensor was investigated by using electroanalytical studies such as cyclic voltammetry and chronoamperometry analysis. The enhanced surface area with a cubic structure of ZnFe(PBA) and the excellent electrical response of Ti3C2 nanosheet support the advancement of a non-enzymatic electrochemical glucose sensor with improved sensitivity of 973.42 µA mM−1 cm−2 with the limit of detection (LOD) of 3.036 µM (S/N = 3) and linear detection range (LDR) from 0.01 to 1 mM.

Electrochemical non-enzymatic glucose biosensors based on Au-thiol-linked molecular architectures

In this work, an electrochemical non-enzymatic glucose sensor consisting of di-methanethiol-grafted poly (3,4-propylenedioxythiophene), gold nanoparticles (Au NPs), and reduced graphene oxide (rGO) was synthesized by a one-step method through Au-S chemisorption. The structure and morphology of the as-prepared poly (ProDOT-(MeSH)2)/Au/rGO composite were characterized by FT-IR, XRD, EDX, TEM, SEM, and XPS, and the electrochemical performance of the composite was investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) on glassy carbon electrode (GCE). The results show that because of the hydrogen bond interaction between the thiol group on the polymer units and the functional groups on GO, poly (ProDOT-(MeSH)2)/Au/rGO was successfully prepared. In addition, due to the unique morphological structure of the composite and the ability to absorb glucose molecules through hydrogen bonds, the poly(ProDOT-(MeSH)2)/Au/rGO electrode possesses excellent selectivity and unique sensitivity (46.13 μA mM−1 cm−2) for sensing glucose in the linear range of 0.04–16.0 mM with a detection limit of (S/N = 3) 0.01. This paper demonstrates that the poly(ProDOT-(MeSH)2)/Au/rGO composite holds great promise for application as a new glucose sensor in life science.

Graphene/PEDOT/Ni-Based electrochemical Non-Enzymatic glucose sensor

Compared to enzymatic glucose sensors, non-enzymatic glucose sensors offer significant advantages in sensitivity, stability, and cost. In this study, a green and simple electrochemical method was employed to prepare an electrochemical non-enzymatic glucose sensor based on graphene/PEDOT/Ni materials. The modified electrode was characterized using scanning electron microscopy (SEM), Raman spectroscopy, Fourier-transform infrared spectroscopy (FTIR), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The electrochemical behavior of glucose on the modified electrode was investigated, and the results indicated that the sensor exhibited a good electrochemical response to glucose. Experimental conditions were optimized, and under the optimal conditions, the sensor showed a good linear relationship with glucose concentration in the range of 0.0001 to 7 mM, with a detection limit of 0.012 μM. The sensitivity was 1561 μA·mM−1·cm−2, demonstrating excellent reliability, stability, and accuracy.

Highly stable and selective determination of glucose by a modified glassy carbon electrode based on micro-rods [Ni(HL)NCS] complex as a novel modifier

Non-enzymatic glucose sensors have acquired a lot of attention, where the modifier materials perform as an electrocatalyst instead of an enzyme on the surface of electrodes. More active sites, increased synergistic reactions, and expanded contacts between the electrolyte and the catalyst are essential to enhance catalytic performances. Numerous efforts have been made to fabricate novel non-enzymatic glucose sensors with electrode modification strategies. Herein, a non-enzymatic electrochemical glucose sensor was constructed by a modified glassy carbon electrode (GCE) based on micro-rods [Ni(HL)NCS] complex (MR-NiC/GCE) as a novel modifier for the glucose detection. In alkali media, the non-enzymatic glucose sensor showed a linear dynamic range (LDR) of 100-1100 µM with an excellent limit of detection (LOD) of 15.8 μM (S/N= 3). The proposed sensor demonstrated remarkable stability (after recording 50 continuous cycles), good reproducibility, and significant anti-interference performance toward fructose (Fru), ascorbic acid (AA), dopamine (DA), citric acid (CA), uric acid (UA) and sucrose. According to this study, complexes can be an excellent suggestion to fabricate non-enzymatic glucose sensors.

NiCo layered double hydroxide nanosheet arrays constructed via in-situ plasma etching as non-enzymatic electrochemical sensor for glucose in food

The design and construction of an efficient non-enzymatic glucose electrochemical sensor is of great significance for food quality assessment. Here, we have developed a method to fabricate highly efficient catalytic electrodes for glucose sensing in alkaline. This method utilizes microplasma assistance during the in-situ etching of NiCo layered double hydroxide nanosheet arrays on nickel foam (NiCo-LDH/NF). The NiCo-LDH nanosheets possessed uniform dispersion without agglomeration, high electrochemically active surface area, and excellent electron transfer efficiency (the electron transfer coefficient (α) up to 0.91, the catalytic rate constant (k) was 2.44 × 106 cm3 mol−1 s−1). The NiCo-LDH/NF-based non-enzymatic glucose sensor exhibits the broad linear range (0.4–150 μM), high sensitivity (98000 μA mM−1 cm−2), and the low detection limits (48.76 nM) with satisfactory reproducibility and selectivity. This work developed a simple and rapid in-situ approach for constructing non-enzymatic electrochemical sensors with high sensitivity.

One-step green synthesis of flower-like non-precious metal (Cu, Ni, Fe or Zn) doped ZIF-67 and its application as non-enzymatic electrochemical glucose sensors

Co ions and imidazolate ligands can be self-assembled into a novel metal-organic frameworks (MOFs) with zeolite-like topological structures, which is named as ZIF-67. Flower-like ZIF-67 can be precisely prepared by one-step green synthesis method under specific experimental conditions, and has excellent enzyme-like electrocatalytic activity toward glucose. Non-precious metal (Cu, Ni, Fe or Zn) can be doped into flower-like ZIF-67 while maintaining zeolite-like topological structures, which may also be an important way to enhance the electrocatalytic performances of ZIF-67. In this study, flower-like non-precious metal (Cu, Ni, Fe or Zn) doped ZIF-67 was contrastively researched by physical characterizations and electrochemical techniques, and was employed as electrocatalysts for non-enzymatic electrochemical glucose sensors. Flower-like non-precious metal (Cu, Ni, Fe or Zn) doped ZIF-67 all exhibits perfect electrocatalytic activities toward glucose, among them the performance of Fe(5 %)-ZIF-67 is the most outstanding.

Directionally Exfoliated Ni/Co Hydroxide-Organic Framework Nanosheets for Enhanced Wearable Glucose Sensing.

We report two-dimensional (2D) Ni/Co-based metal hydroxide-organic framework nanosheets (Ni/Co-MHOF NSs) for the construction of an efficient electrochemical nonenzymatic glucose sensor. The nanosheet architecture maximizes the exposure of coordinatively unsaturated metal sites, which enables a largely improved electrocatalytic performance toward the glucose oxidation reaction. The as-designed nonenzymatic sensor exhibits a high sensitivity of 235.71 μA·mM-1·cm-2 and a wide linear range of 1-3000 μM. The sensor presents excellent selectivity against several potential interferences and a short response time of 3.0 s. Of interest, a high-performance flexible sensor is developed by depositing the Ni/Co-MHOF NSs on screen-printed electrodes, which reveal decent bending stability. The designed glucose sensor patch can attach to the human body and realize noninvasive glucose monitoring in human sweat. This work may shed light on the application of novel MHOFs in the field of wearable electrochemical sensing.

Nanostructured metallic enzymes mimic for electrochemical biosensing of glucose

In many domains, the creation of nonenzymatic glucose sensors with robust electrocatalytic activity and chemical stability is indispensable. However, the design of nanoarchitecture transition metals and their nanocomposites as sensing interfaces for nonenzymatic recognition groups remains a formidable challenge. This review discusses the engineered nanoarchitecture transition metals used as non-enzymatic glucose sensors, with a particular focus on their applications characterized by low cost, high sensitivity, and long-term durability. Central to our discussion is the imperative of crafting nanostructured transition materials with expansive specific surface areas and well-defined active sites to serve as electrochemical sensing platforms. Our objective is to shed light on the enhanced electrochemical behavior toward glucose without reliance on mediators or templates. Leveraging advancements in nanotechnology, this review seeks to elucidate strategies for refining conventional nanostructures to optimize enzyme-free glucose sensing applications. Additionally, we delve into the inherent challenges and potential applications of these sensors for detecting glucose and outline ways to develop better non-enzymatic electrochemical glucose sensors.

Development of Highly Sensitive and Selective Electrochemical Glucose Sensors Based on the Modification of the Surface, Structural, and Morphological Properties of ZnO Using Vitamin-B Complexes

Non-enzymatic electrochemical glucose sensors are particularly advantageous because of their simplicity, low cost, efficiency, and long storage life. ZnO structures were modified with water-soluble vitamin B12, B9, and B6 complexes in alkaline 0.1 M NaOH solutions to enhance glucose sensing. ZnO samples were hydrothermally synthesized using 5 mg fixed masses of B12, B9, and B6 complexes. X-ray diffraction, scanning electron microscopy, UV-visible spectrometry, and Fourier transform infrared spectroscopy were used to determine crystalline properties, morphology, and optical band gap. Zinc oxide obtained from vitamin B complexes had a hexagonal structure similar to wurtzite, modified nanorods on its surface, and a reduced optical band gap. The molecular weight, size, and number of functional groups vitamins also influenced surface and structural characteristics of ZnO. Zinc oxide from the B12 complex proved excellent for non-enzymatic glucose sensing in alkaline conditions. B12-derived ZnO glucose sensors have a linear range of 0.1 to 10 mM with a detection limit of 0.005 mM. In the glucose sensing process, a satisfactory level of stability, reproducibility, and selectivity was observed. Furthermore, it was found that ZnO derived from B12 had a high electrical conductivity, which facilitated electron transfer during glucose oxidation.

Honeycomb-shaped vertically aligned carbon nanotubes decorated with molybdenum trioxide as an electrochemical sensor for glucose

In this study, an electrode based on transition metal oxide molybdenum trioxide (MoO3) was fabricated and applied to electrochemical biosensing for glucose. In the process of making electrodes with relatively larger specific surface areas, an array of carbon nanotubes (CNTs) was deposited on a silicon substrate, and then, MoO3 was coated on the array of CNTs by chemical vapor deposition to produce a MoO3/CNTs/Si structure of three-dimensional electrochemical biosensing electrodes. Biosensing measurement was carried out in the concentration region from 20 μM to 7 mM of sodium hydroxide (NaOH). The highest sensitivity of 17.4 μA/μM cm2 was measured in the concentration range of 20–100 μM. The correlation coefficient of linear response (R2) was 0.9929, thus showing that MoO3/CNTs/Si is an excellent nonenzymatic glucose electrochemical sensor.

Enhanced sensing performance of flexible non-enzymatic electrochemical glucose sensors using hollow Fe3O4 nanospheres of controllable morphologies

Rapid and accurate monitoring of glucose concentration is of great significance in clinical diagnosis and treatment of diabetes and hence, it is necessary to develop glucose sensors of superior electro-catalytic capacity. Most literature utilize synergistic effect of nanocomposites to enhance glucose sensing performance, whereas it suffers from crucial restriction in physical and chemical characteristics of each constituents. Morphology of nanostructures significantly affects the electro-catalytic capacity, thus it is a novel route to improve glucose sensing performance to adjust morphology of nanostructures. Herein, we presented highly sensitive non-enzymatic electrochemical sensors for rapid and accurate glucose analysis with hollow Fe3O4 nanospheres (Fe3O4NSs) of controllable morphologies decorated on flexible fibers. The morphologies of the Fe3O4NSs were evaluated with quantitative parameters like diameter, roundness, roughness, skewness, and kurtosis acquired from SEM images and image processing algorithms, and their effect on the interfacial characteristics and the electro-catalytic capacity of the glucose sensors was investigated. Owing to the unique spherical nanostructures and superior catalysis, the Fe3O4NSs exhibit desirable solid/liquid interface for mass diffusion and abundant active sites for sufficient oxidation of glucose. Moreover, much rounder and rougher Fe3O4NSs of near Gaussian surface are readily produced at a higher Fe3+ concentration and result in favorable sensing performance. Accordingly, the optimal glucose sensor shows sensitivities of 96.1 ± 5.4 μA mM−1 cm−2 and 38.2 ± 2.2 μA mM−1 cm−2 over a preferable range of 0–18.0 mM, and a lower detection limit of 19.2 μM. Besides, the glucose sensors remain acceptable response after continuous testing for 20 times and repetitive bending for 50 times, and display superior selectivity to glucose and accurate analysis to practical samples. It is a facile and effective methodology to regulate the morphologies of the Fe3O4NSs for enhanced electro-catalytic capacity of glucose sensors.

Non-enzymatic Glucose Sensor Based on Ni(OH)2/NF Materials Using Different Pulse Voltammetry Technique

Non-enzymatic glucose sensors have gained significant attention owing to their potential for accurate and cost-effective glucose detection. Nanomaterials play a pivotal role in enhancing performance of non-enzymatic glucose sensor. In this study, a novel non-enzymatic glucose sensor based on Ni(OH)2/NF (nickel hydroxide/nickel foam) materials was developed using different pulse voltammetry technique. Chemical precipitation methods have been used to grow Ni(OH)2 nanostructures directly on a nickel foam electrode. The characterization of the synthesized materials was performed through field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDX), and X-ray diffraction (XRD). The performance of the Ni(OH)2/NF-based glucose sensor was evaluated through electrochemical measurements. Nanoscale hive-like structures of Ni(OH)2 with a diameter ranging from 450 to 530 μm and a thickness of 20 nm were formed on the NF surface. The sensor exhibited good performance, displaying a high sensitivity of 8.42mA.mM-1.cm-2 with a low detection limit of 0.84 μM. These results position the synthesized electrode as a promising contender for non-enzymatic electrochemical glucose sensors.

Tailoring the d-band center on Ru1Cu single-atom alloy nanotubes for boosting electrochemical non-enzymatic glucose sensing.

The development of cost-effective and highly efficient electrocatalysts is critical to help electrochemical non-enzymatic sensors achieve high performance. Here, a new class of catalyst, Ru single atoms confined on Cu nanotubes as asingle-atom alloy (Ru1Cu NTs), with aunique electronic structure and property, was developed to construct a novel electrochemical non-enzymatic glucose sensor for the first time. The Ru1Cu NTs with a diameter of about 24.0nm showed amuch lower oxidation potential (0.38V) and 9.0-fold higher response (66.5 μA) current than Cu nanowires (Cu NWs, oxidation potential 0.47V and current 7.4 μA) for glucose electrocatalysis. Moreover, as an electrochemical non-enzymatic glucose sensor, Ru1Cu NTs not only exhibited twofold higher sensitivity (54.9 μA mM-1cm-2) and wider linear range (0.5-8mM) than Cu NWs, but also showed alow detection limit (5.0μM), excellent selectivity, and great stability. According to theoretical calculation results, the outstanding catalytic and sensing performance of Ru1Cu NTs could be ascribed to the upshift of the d-band center that helped promote glucose adsorption. This work presents a new avenue for developing highly active catalysts for electrochemical non-enzymatic sensors.

Synergistically enhancing electrocatalysis and non-enzymatic sensing for glucose by iridium single-atom/nickel oxide/N-doped graphene.

The development of novel catalyst with high catalytic activity is important for electrochemical non-enzymatic glucose sensing. Here, iridium single-atom/nickel oxide nanoparticle/N-doped graphene nanosheet (Ir1/NiO/NG) with the loading of 1.13 wt% Ir was successfully synthesized for constructing electrochemical non-enzymatic glucose sensor for the first time. The morphology and structure of Ir1/NiO/NG were characterized by XRD, SEM, TEM, HRTEM, and XPS, and the presence of Ir SAs was confirmed by AC-HAADF-STEM. The Ir1/NiO/NG shows 65 mV lower oxidation potential and 3.3 times higher response current than Ni(OH)2/NG. In addition, Ir1/NiO/NG exhibits high sensitivity (70.09 μA mM-1 cm-2), excellent selectivity, low detection limit (2.00 μM), and great stability (91.53% current remaining after 21 days) for electrochemical non-enzymatic glucose sensing. The outstanding catalytic and sensing performance of Ir1/NiO/NG is mainly attributed to synergistic effect of Ir SAs, NiO nanoparticles, and highly conductive NG, which modulate the electronic and geometric structure of Ir1/NiO/NG. This work shows the promising potential of SACs in electrochemical sensing.

Hollow nanocages heterostructured NiCo-LDH/MWCNTs electrocatalyst for highly sensitive and non-invasive detection of saliva glucose

Monitoring salivary glucose has gained increased attention as a non-invasive approach to prevent and diagnose diabetes. Since the glucose concentration in saliva is lower than that in blood, the development of effective electrocatalysts for highly sensitive glucose detection is thus of great significance. In this study, a hollow nanocage from NiCo-layered double hydroxides (LDH) modified with multi-walled carbon nanotubes (MWCNTs) is designed and further employed as the sensing material to construct a novel non-enzymatic glucose electrochemical sensor with high sensitivity. It is synthesized by utilizing pre-synthesized zeolitic imidazolate framework (ZIF-67)/MWCNTs as a sacrificial template and subsequently conducting a simple solvent-thermal reaction with Ni(NO3)2. Such a hollow nanocage preserves the polyhedral framework structure of the used precursor, where the hollow frame-like structure of NiCo-LDH offers accessible catalytic sites, and MWCNTs provides good conductivity. Their combination brings in a bridging effect between MWCNTs and NiCo-LDH, further leading to a large electrochemical active area and excellent catalytic activity of this hollow nanocage. The constructed sensor exhibits a detection limit as low as 0.03 μM for the glucose detection as well as wide linear ranges of 0.1–3000 μM and 3000–9231.8 μM, corresponding to the sensitivity of 2.55 and 1.15 μA mM−1 cm−2, respectively. Moreover, this sensor enables the tracking of glucose concentration change in salivary before and after food intake. This work offers new highly sensitive sensing materials and potentially valuable approaches for non-invasive glucose detection.

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.

A novel NiO/C@rGO nanocomposite derived from Ni(gallate): A non-enzymatic electrochemical glucose sensor

The development of suitable substrate materials in electrochemical sensors is essential for rapid and reliable quantification in the diagnostic and clinical fields. In this paper, NiO/C@rGO nanocomposite was synthesized through nickel (gallate) pyrolysis with graphene oxide and employed as a substrate to construct a glucose sensor with high selectivity and sensitivity. The structural characterizations of NiO/C@rGO were assessed by Fourier transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscopy, energy disperse spectroscopy, and elemental mapping. The newly fabricated biosensor (NiO/C@rGO/GCE) exhibited a high sensing performance with an extensive dynamic linear range (from 1 μM to 1115 μM) and a low limit of detection (LOD) 0.658 μM (S/N = 3) toward glucose. In addition, the NiO/C@rGO-based sensor displayed good stability, favorable repeatability, and anti-interference ability for determining glucose. It was also used to measure glucose in serum samples, and satisfactory results were attained. These results illustrated that the NiO/C@rGO nanocomposite could be applied as an excellent electrochemical sensing material with high sensitivity to diagnose glucose-related illnesses.

Hydrothermally synthesized CuNiS@CNTs composite electrode material for hybrid supercapacitors and non-enzymatic electrochemical glucose sensor

Hydrothermally synthesized CuNiS@CNTs composite electrode material for hybrid supercapacitors and non-enzymatic electrochemical glucose sensor

A novel non-enzymatic electrochemical glucose sensors based on graphene oxide nanoribbons: Tracking energy expenditure and nutritional intake in sports

This work revealed the development of a novel non-enzymatic electrochemical sensor for glucose detection based on a modified glassy carbon electrode made of graphene oxide nanoribbons (GONRs). The TEM, XRD), XPS, FTIR, and Raman spectroscopy were used to characterize the shape and structure of the modified electrode made of GONRs. Using amperometry and cyclic voltammetry (CV), the nanocomposite's electrochemical performance was assessed (AMP). The TEM results support the XPS, Raman, and XRD observations, demonstrating the capability of the suggested approach to generate single-layered GONRs with good edge linearity. The suggested non-enzymatic glucose sensing method was found to be selective, stable, repeatable, and reproducible through electrochemical analyses. The response behavior of GONRs/GCE was found to be linear within the 0.1–105 mM range, and the sensitivity and detection limit were found to be roughly 20.815 µA/mM and 3 µM, respectively. To verify the GONRs/GCE sensor's practicality and viability, tests were conducted on human serum and orange juice samples. The recovery rate ranged from 94.00% to 99.20%, according to the results, and the relative-standard deviation (RSD) values were 3.21% to 4.41%. These encouraging RSD and recovery rates showed that GONRs/GCE would work well as electrodes for measuring glucose in actual samples.