Non-enzymatic Glucose Research Articles

Non-Enzymatic Glucose Sensors Composed of Polyaniline Nanofibers with High Electrochemical Performance.

The measurement of glucose concentration is a fundamental daily care for diabetes patients, and therefore, its detection with accuracy is of prime importance in the field of health care. In this study, the fabrication of an electrochemical sensor for glucose sensing was successfully designed. The electrode material was fabricated using polyaniline and systematically characterized using scanning electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and UV-visible spectroscopy. The polyaniline nanofiber-modified electrode showed excellent detection ability for glucose with a linear range of 10 μM to 1 mM and a detection limit of 10.6 μM. The stability of the same electrode was tested for 7 days. The electrode shows high sensitivity for glucose detection in the presence of interferences. The polyaniline-modified electrode does not affect the presence of interferences and has a low detection limit. It is also cost-effective and does not require complex sample preparation steps. This makes it a potential tool for glucose detection in pharmacy and medical diagnostics.

Facilely prepared Co-based MOF functionalized N, S-doped reduced graphene oxide for electrochemical non-enzymatic glucose sensing

Rational design of modified electrode materials is critical for electrochemical sensors. Metal-organic frameworks (MOFs), a novel sort of substance with porosity, has received widespread attention owing to various superior characteristics such as adjustable pore sizes, great surface area and controllable structures. Nevertheless, the poor charge transfer capability of MOFs leads to a general suppression of their electrochemical sensing performance. To solve this issue, compositing conductive substance with MOFs have been demonstrated to be an effective strategy. Herein, Co-based MOF (ZIF-67) functionalized N, S-doped reduced graphene oxide (N, S-RGO) heterostructure (ZIF-67/N, S-RGO) was fabricated through an in-situ synthesis method. The composite material was used in the modification of an electrode to construct a sensing platform for non-enzymatic glucose testing. The synergistic interaction of ZIF-67 and N, S-RGO not only provided more efficient active sites and larger surface areas, but also improved the electron transport efficiency and electrocatalytic performance. Under optimized conditions, the ZIF-67/N, S-RGO/GCE had a dynamic linear range of 1–3200 μM, with a detection limit of 0.33 μM (S/N = 3) for glucose detection. The sensing platform also provided excellent reproducibility, selectivity, and stability (70 % activity retained after 12 days). Furthermore, the sensor had the potential to apply for glucose determination in human serum. This work presented a novel strategy to the field of non-enzymatic glucose sensing and may provide effective coaching for optimizing the electrochemical sensing performance of other series of MOFs.

Pulsed laser fragmentation synthesis of carbon quantum dots (CQDs) as fluorescent probes in non-enzymatic glucose detection

Pulsed laser fragmentation in liquid (PLFL) is one of the synthesis routes for producing high-purity carbon quantum dots (CQDs) with less toxic by-products in a straightforward system. The limited literature regarding the application of PLFL-synthesized CQDs motivated this study to exploit them as fluorescent probes in glucose sensing. The design of a fluorescent-based non-enzymatic glucose sensor was achieved by implementing CQDs and 3-aminophenylboronic acid (APBA) as fluorescent probes and glucose receptors, respectively. The CQDs were fabricated by PLFL through an Nd:YAG nanosecond laser, starting from the carbon powder dispersion in ethanol. Then, a laser-assisted post-modification process with oxidizing acid was implemented to produce water-dispersible CQDs for easy functionalization. Functionalizing these CQDs with APBA (CQDs-APBA) resulted in a blue-shifted fluorescence emission with a 35% quantum yield and high photostability. The CQDs-APBA exhibited a turn-off response at increasing glucose concentrations. This method offers good sensitivity with a linear detection range of glucose with a concentration of 0.165 to 8 mM and a detection limit of 165 µM. The applicability of this sensor to real analytes such as saliva obtained a satisfactory result with good reproducibility. This work proves that CQDs synthesized from PLFL can also be an alternative fluorescent probe for fluorescent-based sensing applications.

Integrating Cu/CuxO ternary nanocomposites with multi-walled carbon nanotubes enabling a high-performance nonenzymatic amperometric glucose sensor

We developed a new nonenzymatic amperometric glucose sensor by integrating a ternary nanocomposite, Cu/Cu2O/CuO (Cu/CuxO), with multi-wall carbon nanotubes (Cu/CuxO@MWCNTs) as the electrocatalyst. The Cu/CuxO@MWCNTs nanocomposite is prepared via an electroless plating process followed by thermal treatment. The constructed nanocomposites are systematically characterized with a transmission electron microscope, an X-ray diffractometer, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and electrochemical impedance spectroscopy, respectively. The Cu/CuxO@MWCNTs nanocomposites-modified glassy carbon electrodes exhibit high electrocatalytic activity toward glucose electrooxidation under alkaline conditions. The efficient electrocatalytic activity of Cu/CuxO@MWCNTs for glucose electrooxidation is utilized for glucose detection using Cu/CuxO@MWCNTs-modified glassy carbon electrodes. The Cu/CuxO@MWCNTs-modified electrode displays an excellent sensing performance within a wide analyte concentration from 0.005-6,000 M (low detection limit is calculated to be 0.003 μM) with superior stability, selectivity, repeatability, and reproductivity. This as-prepared electrochemical sensor is successfully applied to selective glucose detection with satisfactory results.

Anodized CuO-based reusable non-enzymatic glucose sensor as an alternative method for the analysis of pharmaceutical glucose infusions: a cyclic voltammetric approach.

Analyzing pharmaceutical products is a quality control requirement in a production facility. This study presents a CuO electrode-based reusable non-enzymatic sensor as an alternative method for rapid analysis of glucose levels in glucose infusions. CuO is extensively employed as an electrode material in non-enzymatic glucose sensors. Conventionally, these electrodes are fabricated using chemical synthesis of CuO followed by immobilization to the electrode substrate. In contrast, here, Cu metal was mechanically modified to create a grooved surface, followed by electrochemical anodization and subsequent annealing process to grow a seamless CuO layer in situ with enhanced catalytic activity. The morphology of the electrodes was characterized using scanning electron microscopy (SEM) and X-ray diffractometry (XRD). The direct electrocatalytic activity of the developed CuO-modified electrode towards glucose oxidation in alkaline media was investigated by cyclic voltammetry in detail. The CuO-modified electrode commenced the oxidation process around 0.10V vs. Ag pseudo-reference electrode, demonstrating a significant reduction in the overvoltage for glucose oxidation compared to the bare Cu electrode. The sensor is capable of detecting glucose at low oxidation potentials such as 0.2V with a sensitivity value of 0.37 µA ppm-1, a wide linear range (80-2300ppm), limit of quantification (LOQ) of 1ppm, greater repeatability, 1% precision, 3% bias, a short response time (80s), good reproducibility and excellent reusability (196 consecutive attempts). The enhanced performance and cost-effectiveness make this sensor a promising alternative method for product analysis in glucose injection solutions.

Free-standing arrays of BaTiO3 nanotubes for non-enzymatic glucose sensing & hydrophobic coating applications

BaTiO3 nanostructures have been considered as a promising candidates in recent past for energy and biomedical sectors owing to their excellent physiochemical properties, such as high dielectric constant, excellent piezoelectric property, good biocompatibility, non-linear optical characteristics etc. Present study reveals on free-standing arrays of BaTiO3 nanostructures, were fabricated by hydrothermal conversion of anodic TiO2 nanotubes. Morphological and structural information of the BaTiO3 nanotubes were done using FESEM and XRD studies. FESEM analysis revealed that the fabricated samples were having tubular morphology of average length and pore diameter of 4.63 μm and 290 nm respectively. Cubical perovskite crystalline phase of BaTiO3 was confirmed through XRD analysis. The BaTiO3 nanotube samples had shown a higher sensitivity of 44.43 μA mM−1 cm−2 and a faster response of 0.1 s for glucose detection. The fabricated BaTiO3 nanotubes film also showed a higher contact angle of 122.70°. Therefore, our present fabrication on Titanium foil study emphasizes on arrays of BaTiO3 nanotubes which will open up a new window in the development of various types of sensing and hydrophobic coating applications.

Nonenzymatic dual glucose sensing on boronic acid modified zeolitic imidazolate framework-67 nanoparticles for diabetes management.

For early diabetes identification and management, the progression of an uncomplicated and exceedingly responsive glucose testing technology is crucial. In this study, we present a new sensor incorporating a composite of metal organic framework (MOF) based on cobalt, coated with boronic acid to facilitate selective glucose binding. Additionally, we successfully employed a highly sensitive electro-optical immunosensor for the detection of subtle changes in concentration of the diabetes biomarker glycated haemoglobin (HbA1c), using zeolitic imidazolate framework-67 (ZIF-67) coated with polydopamine which further modified with boronic acid. Utilizing the polymerization characteristics of dopamine and the NH2 groups, a bonding structure is formed between ZIF-67 and 4-carboxyphenylboronic acid. ZIF-67 composite served as an effective substrate for immobilising 4-carboxyphenylboronic acid binding agent, ensuring precise and highly selective glucose identification. The sensing response was evaluated through both electrochemical and optical methods, confirming its efficacy. Under optimized experimental condition, the ZIF-67 based sensor demonstrated a broad detection range of 50-500mg dL-1, a low limit of detection (LOD) of 9.87mg dL-1 and a high correlation coefficient of 0.98. Furthermore, the 4-carboxyphenylboronic acid-conjugated ZIF-67-based sensor platform exhibited remarkable sensitivity and selectivity in optical-based detection for glycated haemoglobin within the clinical range of 4.7-11.3%, achieving a LOD of 3.7%. These findings highlight the potential of the 4-carboxyphenylboronic acid-conjugated ZIF-67-based electro-optical sensor as a highly sensitive platform for diabetes detection.

Non-enzymatic Glucose Detection by Fe2O3 Nanorods-reduced Graphene under Physiological pH

Background: Non-enzymatic detection has become a research hotspot because of its alternativity in solving problems compared to enzymatic biosensors, but most of those sensors require a strong basic pH environment (higher than 10) to active their surface, restricting their use in clinical detection because the pH of body fluid is around 7.4. Furthermore, metal oxide sensors with specific morphologies are reported to have a fast electrocatalytic response. Therefore, Fe2O3 nanocomposites with porous structure are selected for glucose detection research in a physiological pH environment. Objective: The study aimed to assess the potential use of porous reduced graphene oxide-Fe2O3 nanorods in glucose detection in a physiological pH environment. Method: Hydrothermal method was used to prepare porous Fe2O3-rGO NRs (Nanorods) and hollow Fe2O3/C nanoparticles. Cyclic voltammetry and electrochemical impedance spectroscopy were used to evaluate the performance of our materials. Results: Porous-reduced graphene oxide-Fe2O3 nanorods have exhibited better performance than hollow carbon-Fe2O3 core-shell nanoparticles for glucose detection in a physiological pH environment. Conclusion: Non-enzymatic glucose sensing based upon cavity Fe2O3-rGO NRs under a physiological pH environment has been successfully realized, attributing to their high electron mobility and large specific surface area. Furthermore, the results of this work indicate that the glucose sensor prepared here has shown good repeatability and stability, which suggests its potential use in clinical detection.

Iodine-doped reduced graphene oxide and titanium dioxide nanocomposite as effective amperometric glucose biosensor

The current study fabricated a non-enzymatic glucose sensor based on iodine-doped reduced graphene oxide with titanium dioxide (I-rGO@TiO2) nanocomposite. Initially, the sol-gel and thermal reduction methods synthesized titanium dioxide (TiO2) nanoparticles and reduced graphene oxide (rGO). Then, the hydrothermal technique was utilized to synthesize a composite of I-rGO@TiO2 by combining I-rGO and TiO2 in a 1:4 ratio. The XRD spectrum and TEM images revealed that in the I-rGO@TiO2 nanocomposite, nanocrystalline anatase titanium is randomly distributed on the I-rGO sheets. Fourier transforms the infrared spectrum of nanocomposite shows the presence of titanium and oxygen bond characteristics peak between 400 and 850 cm−1. Iodine molecules peak at 100 cm−1 were obtained in Raman spectra. The AC conductivity and dielectric properties of the nanocomposite were analyzed. For the sensor fabrication, the indium tin oxide electrode surface is modified by I-rGO@TiO2, and the electrochemical performance was examined. At room temperature, the sensor demonstrated a wider linear detection range (0.5−10 mM). The lower detection limit of the sensor was 0.23 μM (S/N = 3), and the sensitivity was 221.69 μA mM−1 cm−2. The I-rGO@TiO2 nanocomposite shows a positive temperature coefficient via the thermal activation of charge carriers and a conductivity of 3.82 × 10−5 Ω−1m−1 at 200 °C. Additionally, the antibacterial properties was evaluated, and dose-dependent properties were observed towards E. coli and Bacillus subtilis bacterium.

Electrochemical Non-Enzymatic Glucose Sensing Platform Based on Vanadium Pentoxide Film-Modified Screen Printed Gold Electrode

A screen printed gold electrode (SPGE) served as the foundation for directly depositing Vanadium pentoxide (V2O5), crafting an enzyme-free glucose sensor. Through cyclic voltammetry in an alkaline setting, the sensor's ability to drive glucose oxidation was explored. Utilizing V2O5 as an electrocatalyst, this non-enzymatic sensor exhibited an expansive linear detection range (1 mM–10 mM) and an impressively low detection limit of 0.9 μM. These results underscored V2O5's robust electrocatalytic process in facilitating glucose oxidation within alkaline solutions, unaffected notably by substances like ascorbic acid, fructose and maltose. This investigation highlights a direct and efficient method for glucose detection without reliance on enzymes.

Construction of Pt/Ni/NiFe2O4/C nanocomposite with one dimensional hollow structure for portable glucose sensing application.

Designing portable electrochemical sensors combined with highly efficient glucose oxidation electrodes offers a significant opportunity for convenient glucose detection. In this report, we present the design and preparation of platinum deposited Ni/NiFe2O4/Carbon composite (Pt/Ni/NiFe2O4/C) derived from Ni/Fe metal-organic frameworks (MOFs) followed by Pt deposition. Energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and electron microscopy (EM) were utilized to analyze the crystal structure, morphology, and chemical composition of the resulting materials. The glucose sensing capabilities of the optimal Pt/Ni/NiFe2O4/C-3 were assessed using amperometry methods on a smartphone-based portable device. Acting as a nonenzymatic glucose sensor, the Pt/Ni/NiFe2O4/C-3 electrode demonstrated notable sensitivity and a low limit of detection for glucose. The portable sensor exhibits high sensitivities of 131.88μM mM cm-2 at low glucose concentration (3-500μM) and 29.52 μA mM cm-2 at high glucose concentration (700-4000μM), achieving a low detection limit of 1.1μM (S/N = 3). The sensor also demonstrates enhanced selectivity and stability for detecting glucose. Furthermore, the portable sensor exhibits a clear step-ampere response in the detection of serum samples with satisfactory recovery ranging from 99.30 to 101.32%. This suggests the significant potential of portable glucose sensing applications.

Revolutionizing Glucose Monitoring: Enzyme-Free 2D-MoS2 Nanostructures for Ultra-Sensitive Glucose Sensors with Real-Time Health-Monitoring Capabilities.

The growing requirement for real-time monitoring of health factors such as heart rate, temperature, and blood glucose levels has resulted in an increase in demand for electrochemical sensors. This study focuses on enzyme-free glucose sensors based on 2D-MoS2 nanostructures explored by simple hydrothermal route. The 2D-MoS2 nanostructures were characterized by powder X-ray diffraction, energy-dispersive X-ray spectroscopy, scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, and XPS techniques and were immobilized at GCE to obtain MoS2-GCE interface. The fabricated interface was characterized by electrochemical impedance spectroscopy which shows less charge transfer resistance and demonstrated superior electrocatalytic properties of the modified surface. The sensing interface was applied for the detection of glucose using amperometry. The MoS2-GCE-sensing interface responded effectively as a nonenzymatic glucose sensor (NEGS) over a linearity range of 0.01-0.20 μM with a very low detection limit of 22.08 ng mL-1. This study demonstrates an easy method for developing a MoS2-GCE interface, providing a potential option for the construction of flexible and disposable nonenzymatic glucose sensors (NEGS). Moreover, the fabricated MoS2-GCE electrode precisely detected glucose molecules in real blood serum and urine samples of diabetic and nondiabetic persons. These findings suggest that 2D-MoS2 nanostructured materials show considerable promise as a possible option for hyperglycemia detection and therapy. Furthermore, the development of NEGS might create new prospects in the glucometer industry.

One-step laser-induced Cu-embedded graphene for non-enzymatic glucose sensing in beverages

The detection of glucose in beverages is crucial for dietary management and healthcare. Excessive sugar consumption can lead to severe conditions, such as obesity, diabetes, cardiovascular diseases, and cancer. In this study, Cu-embedded laser-induced graphene (Cu/LIG) materials were fabricated for non-enzymatic glucose detection using a simple, direct, and cost-effective laser-patterning method on a Cu2+/ethyl-cellulose/polyimide membrane. The experimental results showed that the Cu/LIG electrode exhibited lower charge transfer resistance and a distinct diffusion process compared to the LIG electrode. This improvement can be attributed to the optimized graphene formation achieved by employing ethyl-cellulose (EC) and CuCl2 as combustion promoters. Under optimal conditions, Cu/LIG-600 demonstrated excellent electrocatalytic activity for glucose oxidation, with a low response concentration (5 μM), fast response time (2.0 s), and detection ranges of 0.005–0.525 mM (I-t) and 0.5–4.0 mM (CV). Moreover, the sensor exhibited high selectivity, stability (retaining over 90 % activity after 28 days), and satisfactory recovery rates for spiked glucose in Cola, Sprite, Black Tea, and sugarless Soda Water, indicating its potential for non-enzymatic glucose detection in beverages.

MOF-derived NiCo hydroxide for highly efficient non-enzymatic glucose biosensing

An efficient and robust electrocatalyst is significant for glucose biosensing. The emergence of metal–organic framework (MOF) derived materials opens up new avenues for the development of high-performance glucose sensing catalysts. Herein, MOF derived nickel-cobalt hydroxide supported on conductive copper sheet (NiCo-OH/Cu sheet) is prepared at room temperature. The as-obtained NiCo-OH is endowed with three-dimensional network structure which enables the effective exposure of active materials, sufficient contact between glucose molecule and catalyst. The NiCo-OH/Cu sheet is revealed as good glucose electrochemical sensing material with a wide linear range of 0.05∼6.0 mM and a high sensitivity of 1340 μA mM−1 cm−2. Additionally, the as-fabricated NiCo-OH/Cu sheet displays good anti-interference ability and long-term stability.

Electrodeposition of Ni-Cu alloy electrodes in sulfate–citrate medium and their use for non-enzymatic glucose oxidation

Electrodeposition of Ni-Cu alloy electrodes in sulfate–citrate medium and their use for non-enzymatic glucose oxidation

In situ anchored ternary hierarchical hybrid nickel@cobaltous sulfide on poly(3,4-ethylenedioxythiophene)-reduced graphene oxide for highly efficient non-enzymatic glucose sensing.

A ternary hierarchical hybrid Ni@CoxSy/poly(3,4-ethylenedioxythiophene)-reduced graphene oxide (Ni@CoxSy/PEDOT-rGO) is rationally designed and in situ facilely synthesized as electrocatalyst to construct a binder-free sensing platform for non-enzymatic glucose monitoring through traditional electrodeposition procedure. The as-prepared Ni@CoxSy/PEDOT-rGO presents unique hierarchical structure and multiple valence states as well as strong and robust adhesion between Ni@CoxSy/PEDOT-rGO and GCE. Profiting from the aforementioned merits, the sensing platform constructed under optimal conditions achieved a wide detection range (0.2μM ~ 2.0mM) with high sensitivity (1546.32 μA cm-2mM-1), a rapid response time (5s), an ultralow detection limit (0.094μM), superior anti-interference performance, excellent reproducibility and considerable stability. Furthermore, the sensor demonstrates an acceptable accuracy and appreciable recoveries ranging from 90.0 to 102.0% with less than 3.98% RSDin human blood serum samples, indicating the prospect of the sensor for the real samples analysis. It will provide a strategy to rationally design and fabricate ternary hierarchical hybrid as nanozyme for glucose assay.

AuNi bimetallic aerogel with ultra-high stability applied in smart and portable biosensing

Glucose detection is of significant importance in providing information to the human health management. However, conventional enzymatic glucose sensors suffer from a limited long-term stability due to the losing activity of the enzymes. In this work, the AuNi bimetallic aerogel with a well-defined nanowire network is synthesized and applied as the sensing nanomaterial in the non-enzymatic glucose detection. The three-dimensional (3D) hierarchical porous structure of the AuNi bimetallic aerogel ensures the high sensitivity of the sensor (40.34 μA mM−1 cm−2). Theoretical investigation unveiled the mechanism of the boosting electrocatalytic activity of the AuNi bimetallic aerogel toward glucose. A better adhesion between the sensing nanomaterial and the screen-printing electrodes (SPEs) is obtained after the introduction of Ni. On the basis of a wide linearity in the range of 0.1–5 mM, an excellent selectivity, an outstanding long-term stability (90 days) as well as the help of the signal processing circuit and an M5stack development board, the as-prepared glucose sensor successfully realizes remote monitoring of the glucose concentration. We speculate that this work is favorable to motivating the technological innovations of the non-enzymatic glucose sensors and intelligent sensing devices.

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.

γ-Fe2O3 modified exfoliated graphite flexible paper based non-enzymatic glucose sensor

We report the γ-Fe2O3 modified exfoliated graphite (γ-Fe2O3@ExGCP) flexible paper electrode as a non-enzymatic glucose sensor. The γ-Fe2O3 was physically mixed with exfoliated graphite flakes, and mechanically pressed to get a thin sheet. The amperommetric analysis of γ-Fe2O3@ExGCP electrode shows that the sensor current increases with increasing glucose concentration. The impedance analysis of γ-Fe2O3@ExGCP substantiates the reduction in charge transfer resistance with increasing glucose concentration. The observed values of sensitivity for Ex-GCP and γ-Fe2O3@ExGCP electrodes are 3.51 µA mM-1cm−2 and 7.1 µA mM-1cm−2, respectively. The calculated LOD is 512 μM for γ-Fe2O3@ExGCP. Thus, γ-Fe2O3@ExGCP flexible electrode may be used for non-enzymatic glucose sensor with enhanced sensitivity.