Electrochemical Glucose Sensor Research Articles

Smart sensing flexible sutures for glucose monitoring in house sparrows.

There is a need for flexible chemical sensors for the ecological and physiological research of avian species such as house sparrows (Passer domesticus). Current methods in this field are invasive and require multiple physical interactions with the birds. Emerging research in flexible bioelectronics can enable realization of implantable devices that are mechanically compliant with the underlying tissues for continuous real-time sensing in situ. However, challenges still remain in forming an intimate flexible interface. One of the promising flexible bioelectronic platforms for tissue-embedded sensing is based on functionalizing surgical sutures or threads. Threads have three-dimensional flexibility, high surface-area-to-volume ratio, inherent wicking properties, and are easily functionalizable using reel-to-reel dip coating. Threads are ideal as they are lightweight, therefore, would not interfere with flight motion and would only require minimal interaction with the bird. However, the challenge remains in achieving a highly conductive yet flexible electrode for electrochemical sensing using materials such as gold. In this study, we address this issue through novel gold deposition directly on thread substrate followed by enzyme immobilization to realize flexible electrochemical glucose biosensors on medical-grade sutures. These sensors were calibrated and tested in a range that is wide enough to include the expected range of glucose concentration in house sparrows (0-8.55 mM). Glucose monitoring in house sparrows will provide insights into energy metabolism and regulation during stress responses. In addition, the stability, repeatability, and selectivity of the sensor were tested with final validation in a real bird. Our innovative gold-coated, thread-based flexible electrochemical glucose sensor can also be used in other small and large animals. This can also be extended to monitoring other metabolites in future.

Advances in nanostructured material-based non-enzymatic electrochemical glucose sensors.

Non-enzymatic electrochemical sensors that use functional materials to directly catalyze glucose have shown great promise in diabetes management, food control, and bioprocess inspection owing to the advantages of high sensitivity, long-term stability, and low cost. Recently, in order to produce enhanced electrochemical behavior, significant efforts have been devoted to the preparation of functional materials with regular nanostructure, as it provides high specific surface area and well-defined strong active sites for electrochemical sensing. However, the structure-performance correlation in this field has not been reviewed thoroughly in the literature. This review aims to present a comprehensive report on advanced zero- to three-dimensional nanostructures based on the geometric feature and to discuss in depth their structural effects on enzyme-free electrochemical detection of glucose. It starts by illustrating the sensing principles of nanostructured materials, followed by a detailed discussion on the structural effects related to the features of each dimension. The structure-performance correlation is explored by comparing the performance derived from diverse dimensional architectures, which is beneficial for the better design of regular nanostructure to achieve efficient enzyme-free sensing of glucose. Finally, future directions of non-enzymatic electrochemical glucose sensors to solve emerging challenges and further improve the sensing performance are also proposed.

A sensitive non-enzymatic electrochemical glucose sensor based on a ZnO/Co3O4/reduced graphene oxide nanocomposite

A novel sensitive and selective ZnO/Co3O4/rGO nanocomposite was fabricated using a hydrothermal method and used as a non-enzymatic electrochemical sensor for the detection of glucose.

Research progress of electrode materials for non-enzymatic glucose electrochemical sensors

Glucose biosensors are mainly divided into two types.

Development of glucose sensor based on cobalt and nickel doped ceria nanostructures

In this study, we report the development of a novel and effective electrochemical sensor for non-enzymatic glucose enhanced detection through Ni/Co doped ceria electrocatalysts instead of pristine ceria. The synthesized pristine and doped ceria nanostructures were characterized through X-ray diffraction, scanning electron microscopy and diffused reflectance spectroscopy (DRS). The electrochemical response of the ceria modified glassy carbon electrodes for the non-enzymatic detection of glucose was monitored through cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and chronoamperometry. Results indicate that Ni doped CeO2 and Co doped CeO2 show high sensitivity towards glucose in basic medium with sensitivity values of 11.1 µA/mM cm2 and 184 µA/mM cm2 respectively. The Ni/CeO2 and Co/CeO2 based sensor can detect glucose in a sample up to limits of 80 µM and 16 µM. The efficacy of the fabricated sensors is further demonstrated by EIS, where Co/CeO2 modified electrode shows much lower charge transfer resistance (Rct = 1107 Ω) compared to Ni/CeO2 modified GCE (Rct = 4337 Ω). Amperometric studies indicate a rapid response time (<10 s). The developed biosensors are also highly selective towards glucose amid various interfering species, including uric acid and ascorbic acid. Overall, the Co doped ceria nanostructures serve as efficient electrocatalyst for glucose due to greater electroactivity, high selectivity and sensitivity, low detection limit, and long-term stability.

Highly efficient non-enzymatic electrochemical glucose sensor based on carbon nanotubes functionalized by molybdenum disulfide and decorated with nickel nanoparticles (GCE/CNT/MoS2/NiNPs)

Glucose detection using sensing materials has lately received interest due to the increased demand for sensitive and selective glucose sensors in pharmaceutical, clinical, and industrial settings. Carbon nanotubes (CNTs) are used intensively as a specific class of effective electrode substances in electrochemical sensing due to their large surface area and interesting physical and electrochemical characteristics. Nickel is an attractive transition metal for glucose electrooxidation with high catalytic activity. In this study, CNT/MoS2/NiNPs nanocomposites with different CNT/MoS2 ratios have been prepared by a hydrothermal reaction. The CNT/MoS2 nanocomposites were characterized by X-ray diffraction (XRD), Raman spectroscopy and Fourier transform infrared spectroscopy (FTIR), and their morphology and composition were characterized by field emission scanning electron microscopy (FESEM). Electrocatalytic activity of the as-prepared nanomaterials towards glucose oxidation was investigated by cyclic voltammetry and amperometry in alkaline media. An excellent sensitivity value of 1212 μA·mM−1·cm−2 with a wide linear range (0.05–0.65 mM), a low detection threshold of 0.197 μM and a short response time (3 s) were achieved by the hybrid CNT/MoS2/NiNPs sensor. Its superior catalytic activity and low cost make this hybrid very promising for applications in the direct sensing of glucose.

Hollow Spherical NiCo2O4 and Gold Nanoparticle Composite for Electrochemical Non-Enzymatic Glucose and H2O2 Sensing

A novel electrochemical non-enzymatic sensor for glucose and H2O2 based on metal organic framework (MOF)-derived cobalt-nickel bimetallic oxides (NiCo2O4) and gold nanoparticle (AuNPs) composite modified glassy carbon electrode (GCE) was fabricated in this paper. The structure and morphology of the prepared materials was successfully characterised by X-ray diffraction (XRD), element mapping images and scanning electron microscopy (SEM). Moreover, the electrocatalytic activity for glucose and H2O2 was investigated at the NiCo2O4/AuNPs/GCE using cyclic voltammetry (CV) and amperometric i–t technique. The catalytic currents for glucose and H2O2 are proportional to their concentrations in the range of 0.2 μM–581 μM and 0.5 μM–1774.5 μM, respectively. The corresponding limits of detection (LOD) were calcuated be 0.0081 μM and 0.181 μM for glucose and H2O2. Furthermore, the NiCo2O4/AuNPs/GCE shows excellent stability, reproducibility and anti-interference ability.

Non-enzymatic electrochemical glucose sensor based on Pt2Pd1 alloy nanocrystals with high-index facets

Nanocrystals enclosed by high-index facets (HIFs) have drawn considerable attention due to their large number of low coordinate atoms, as well as their remarkable electrical properties and catalysis activity. In this article, a novel non-enzymatic electrochemical glucose sensor based on the Pt2Pd1 alloy nanocrystals (NCs) with HIFs was established. The mechanism of enhancing sensor performance was investigated by analyzing the composition and surface texture of Pt2Pd1 alloy NCs. The results showed that as-synthesized Pt2Pd1 alloy NCs had a larger electrochemical active surface area (ECSA). In neutral media, all the test results demonstrated the non-enzymatic glucose sensor based on Pt2Pd1 alloy NCs showed a good linear range of 1 × 10–6 M to 4 × 10–2 M with a detection limit of 0.245 μM/L (S/N = 3), good sensitivity of 31.3 μA mM–1 cm–2 and fast response time (t < 3 s). Furthermore, the sensor also exhibited good stability, reproducibility, and excellent anti-interference performance toward ascorbic acid (AA), uric acid (UA), and fructose (Fru). The HIFs and synergistic effects between Pt and Pd were key factors for sensor performance enhancement.

Au Nanoparticles-Modified NiCo₂O₄ Nanowires-Supporting Co₃O₄ Dodecahedron as High-Performance Nonenzymatic Glucose Sensor

A hierarchically nanostructured active material composed of nanoparticles, microsized dodecahedron, and nanowires (NWs) has been successfully fabricated and used for glucose oxidation, in which the NiCo2O4 NWs were grown in situ on the carbon paper (CP) and used for supporting the zeolitic imidazolate framework (ZIF-67)-derived Co3O4 dodecahedron, with the Au nanoparticles (Au-Np) being further electrodeposited on their surface (Au-Np/Co3O4/NiCo2O4 NWs/CP). The NWs effectively avoid the agglomeration of Co3O4, thus providing greater surface area for loading the Au nanoparticles. The introduction of Au can decrease the oxidation potential and enhance the catalytic current, which is beneficial for the electrocatalytic oxidation of glucose. The Au-Np/Co3O4/NiCo2O4 NWs/CP-based nonenzymatic glucose sensor exhibits good sensing performance, including high sensitivity of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$15.3~\mu \text{A}/\mu \text{M}$ </tex-math></inline-formula> /cm2, outstanding response/recovery times of 2.5/4.0 s (toward 180- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{M}$ </tex-math></inline-formula> glucose), good reproducibility, and excellent selectivity. Therefore, constructing a hierarchical nanocomposite is a promising strategy to develop a nonenzymatic electrochemical glucose sensor.

Nanostructured Nickel-based Non-enzymatic Electrochemical Glucose Sensors.

Glucose detection is considered a significant area and has remained the topic of considerable attention. Remarkable technological advancements have been observed in diabetes monitoring in the past decades. This continual progress helps to track recent trends in development as well as identify challenging issues in glucose sensor construction. Thus, a comprehensive synopsis of the most recent advancements and developments in the study of nickel (Ni) nanostructure-based sensors for efficient trace-level glucose detection, following non-enzymatic and electrochemical methods, is provided in this review. Moreover, this review is intensively focused on the methodologies for the structure, morphology, preparation, and enforcement of a variety of Ni nanostructures, including Ni nanosheets with metals, Ni nanospheres with metals/mixed metals, Ni-metal nanocomposites, metal nanoparticles-decorated Ni nanowires, Ni nanoparticles, Ni-decorated metal nanotube arrays, Ni nanoneedles and nanorods with metals, nanoporous, nanoplates, nanocoated Ni with metal composites, and Ni-composed hybrid nanostructures. Various demonstrations and categorizations are provided on Ni-based nanostructures for a clear understanding for diverse readers.

Cost effective synthesis of Mn doped NiO/rGO nanocomposite for non-enzymatic electrochemical glucose sensor

ABSTRACT Herein, we report the synthesis, characterisation and glucose sensor study of prepared compounds and composite. The prepared samples reported here for glucose-sensing applications were doped (Mn.NiO) and un-doped metal oxide (NiO) and their composite with 2D layered material (Mn-doped-NiO/rGO). The structural analysis of the samples was done by conventional technique called as X-rays diffraction (×RD). Spectral and functional groups’ analysis was elucidated by FTIR spectroscopy. The electron microscopy (SEM) was used for morphological features study. The electrochemical measurements were carried out to analyse biosensing response. Carbon fibre cloth was used as a substrate material to fabricate Mn-doped-NiO/rGO nanocomposite-based biosensor for glucose detection. The analytical performance of the synthesised material was evaluated in terms of electrochemical sensitivity, linear response and limit of detection (LOD). The results showed that the material exhibited an excellent electrochemical sensitivity towards glucose detection with wider range of linear responses. The LOD for Mn-doped-NiO/rGO nanocomposite was 0.11 µM, regression equation for the low concentration was I(µA) = 1477.1C + 165.19 with correlation coefficient value R2 = 0.9849. Conclusively, the rGO-based Mn-doped-NiO nanocomposite experienced robust potential as non-enzymatic sensor for detection of glucose.

Electrochemical Synthesis of Shape‐controlled Cu−Ni Nanocomposite and its Application for Nonenzymatic Glucose Sensing at Nanomolar Level

AbstractThe electrodeposition method was firstly applied to obtain uniform cube‐shaped copper nanoparticles on conductive glass (ITO), and then a layer of tiny nickel nanoparticles. A bimetallic composite electrode (Cu−Ni/ITO), characterized by TEM, XPS and XRD, was prepared to construct the non‐enzyme electrochemical glucose sensor with high catalytic activity. The catalytic performance of Cu−Ni/ITO had been greatly improved, probably due to the synergistic bimetallic catalysis effect. The electrode had a satisfactory linear response in the range of 2.5×10−7 M to 2.6×10−3 M, with detection limit as low as 67 nM. Besides, Cu−Ni/ITO had good anti‐interference ability and reproducibility, indicating the promising application for glucose detection in practical samples.

Instant Facile Method for the In Situ Growth of Ni(OH)2 Nanohives on Nickel Foam for Non-Enzymatic Electrochemical Glucose Sensor

Glucose sensor has attracted the attention of academic and industrial researchers because of its broad applications in diabetes management, food quality control, and bioprocess inspection. Compared with enzymatic glucose sensors, non-enzymatic glucose sensors are more relevant because of their stable, sensitive, and low-cost process. The simple and low-cost synthesis of advanced nanomaterials for a non-enzymatic glucose sensor is vital in practical applications. Here, we introduce a facile chemical method for the direct synthesis of nickel(II) hydroxide nanostructures on porous nickel foam (NF) for an electrochemical glucose sensor. The properties of the synthesized material were characterized by field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, high-resolution transmission electron microscopy, selected area electron diffraction, and Raman spectroscopy. The fabricated materials were applied for glucose concentration measurement in 0.1 M NaOH by cyclic voltammetry and chronoamperometry. The Ni(OH)2/NF sensor is stable and has excellent sensitivity (12.55 mA mM−1 cm−2) with a low detection limit of 57 μM (S/N = 3) and high selectivity for glucose detection in the presence of common interfering species. The Ni(OH)2/Ni electrode was successfully tested in measuring glucose concentration in real serum samples. The fabricated Ni(OH)2/NF electrode can be used as a low-cost, sensitive, stable and selective platform for non-enzymatic glucose sensors.

Atomic-scale interfacial engineering enables high-performance electrochemical glucose detection

Developing noble-metal free electrocatalysts with high sensitivity is critical for the large-scale application of electrochemical glucose sensors. This work reports an atomic-scale interfacial engineering strategy to construct highly-active electrocatalyst for glucose detection. Ni(OH)2 nanosheets are decorated with an ultra-thin layer of Co9S8 using the atomic layer deposition (ALD) technique. After in-situ reconstruction, we obtain Ni@Co heterostructure composed of Ni hydroxide nanosheets and CoOx clusters, which exhibits outstanding electrochemical glucose sensing performance. Combining synchrotron-based X-ray adsorption spectroscopy, in situ Raman Spectroscopy, intermittent electrochemical measurements and density functional theory (DFT) calculations, we find that the presence of surface CoOx not only lowers the valence state of Ni, but also facilitates the deprotonation of Ni(OH)2 to form NiOOH active species for glucose oxidation. The approach used in this work can be adapted to synthesizing high-performance electrocatalysts for other energy and environmental devices.

Sandwich structure confined gold as highly sensitive and stable electrochemical non-enzymatic glucose sensor with low oxidation potential

• Fe 3 O 4 @Au@CoFe-LDH is prepared through a spontaneous galvanic displacement reaction. • In Fe 3 O 4 @Au@CoFe-LDH, the metallic Au intercalates between Fe 3 O 4 and LDH forming the sandwich structure. • Fe 3 O 4 @Au@CoFe-LDH possesses high sensitivity of 6342 μA mM −1 cm −2 , broad linear detection range of 0.0375 to 15.64 mM and low limit of detection of 12.7 μM, with an extremely low oxidation potential of 0.82 V vs. RHE. • The small quantity of Au laying between LDH and Fe 3 O 4 is the active part of glucose oxidation and the existence of Fe 3 O 4 nanoparticles significantly improves the stability of the electrocatalyst. The preparation of highly sensitive and stable non-enzymatic glucose sensors is critical to the prevention and treatment of diabetes. Fe 3 O 4 @Au@CoFe-LDH is prepared through a spontaneous galvanic displacement reaction. A series of structural characterizations testify the successful formation of Fe 3 O 4 @Au@CoFe-LDH electrocatalyst, with the Au intercalating between Fe 3 O 4 and LDH to form the sandwich structure. Cyclic voltammetry tests indicate that Au is responsible for the electrocatalytic oxidation of glucose. The characterizations of the electrochemical sensor for glucose detection indicate that Fe 3 O 4 @Au@CoFe-LDH possesses high sensitivity of 6342 μA mM −1 cm −2 , with an extremely low oxidation potential of 0.82 V vs. RHE. Even with the high glucose concentration of 15 mM, the sensitivity remains at 4359 μA mM −1 cm −2 . Due to the broad linear detection range (0.0375 to 15.64 mM) and the low limit of detection (12.7 μM), Fe 3 O 4 @Au@CoFe-LDH is applicable towards practical application. Thanks to the sandwich structure, which confines the Au in between Fe 3 O 4 and CoFe-LDH, the Fe 3 O 4 @Au@CoFe-LDH glucose sensor shows high long-term stability and satisfactory selectivity. The successful synthesis of the sandwich-structured Fe 3 O 4 @Au@CoFe-LDH provides a new conception for the design of highly sensitive and stable non-enzymatic glucose electrodes.

A novel and ultrasensitive non-enzymatic electrochemical glucose sensor in real human blood samples based on facile one-step electrochemical synthesis of nickel hydroxides nanoparticles onto a three-dimensional Inconel 625 foam

A novel and ultrasensitive non-enzymatic electrochemical glucose sensor in real human blood samples based on facile one-step electrochemical synthesis of nickel hydroxides nanoparticles onto a three-dimensional Inconel 625 foam

Effects of nickel–cobalt material properties on glucose catalysis

The development of non-enzymatic glucose sensors becomes even more significant as the number of diabetics worldwide continues to increase. Ni–Co alloy can be fabricated by electrodeposition and used as a catalyst for glucose so that it is a suitable electrode material for non-enzymatic electrochemical glucose sensors. The results of material analyses reveal that the catalytic performance for glucose is related to the crystallographic structure of Ni–Co alloy. A Ni–Co based non-enzymatic glucose sensor with a majority of hexagonal close packed (hcp) lattice exhibits better catalytic performance and, moreover, the catalysis of glucose is a quasi-reversible redox process, either in film-type or nanowire-type alloy. However, the nanowire-type Ni–Co glucose sensor has a wider sensing range than the film-type sensor. Ni–Co glucose sensor possesses excellent anti-interference without being influenced by the chemicals coexisting with glucose. These results demonstrate the effect of the crystal structure of Ni–Co on glucose catalysis and suggest the electroplating conditions for the preparation of Ni–Co non-enzymatic glucose sensor with good catalytic performance and excellent anti-interference ability.

Engineering Co3O4 with Co defects for highly sensitive nonenzymatic detection of glucose

Defect engineering was considered as an effective strategy to regulate electrocatalytic activities of transition metal oxides. However, there are seldom reports about metal defects in electrochemical sensing. In this work, Co-defected Co3O4 was synthesized via thermal treatment of glycerolatocobalt (CoGly) precursor for constructing a novel electrochemical nonenzymatic glucose sensor. The obtained nanomaterials were characterized by transmission electron microscopy (TEM), powder X-ray diffractometry (XRD), Raman spectra, X-ray photoelectron spectroscopy (XPS) and electrochemical techniques. The presence of Co defects regulated electronic structure of Co3O4, which not only speeds up electron transfer rate but also exposes more high-valent Co sites, thus improving electrocatalytic activities. Under optimized conditions, Co-defected Co3O4 electrode exhibited excellent performance for glucose analysis with a wide linear range of 0.2 µM to 0.5 mM, a low detection limit of 0.16 µM. Importantly, an ultrahigh sensitivity of 2595.7 µA·mM−1·cm−2 was also obtained, which was about 10 times higher than that of conventional Co3O4. Therefore, engineering Co3O4 with Co defects is an effective strategy to tailor electrocatalytic activity, which sheds light on the potential applications of metal defects in the field of electrochemical nonenzymatic sensing.

An effective metal-organic framework-based electrochemical non-enzymatic glucose sensor

• Non-enzymatic glucose sensor based on MOF for long-term glucose monitoring. • Excellent electrocatalytic behaviour of Ni-BDC-NH 2 towards oxidation of glucose. • Ni-BDC-NH 2 displayed a lower detection limit, higher stability and sensitivity. • NH 2 functional group has facilitated the electron transfer during glucose detection. • Molecular sieve effect in the MOF enabled the selective diffusion of glucose. Herein, we report a non-enzymatic glucose sensor based on a metal-organic framework (MOF) as alternative approach for long-term glucose monitoring. Specifically, nickel-based MOFs were solvothermally synthesized using either 2-amino-1,4-benzenedicarboxylic acid (BDC-NH 2 ) or 2-hydroxy-1,4-benzenedicarboxylic acid (H 2 BDC-OH), both of which were characterized by different physicochemical techniques. The electrochemical performance of both electrodes towards glucose sensing was investigated and Ni-BDC-NH 2 exhibited a significantly better electrocatalytic behaviour towards oxidation of glucose than bare Ni-BDC or Ni-BDC-OH in an alkaline media. This was attributed to a favourable multi-layered sheet-like structure that allowed diffusion for entrapment of glucose and the incorporation of –NH 2 functional groups attached to the BDC linker which, were responsible for electrochemical adsorption of glucose molecules. Ni-BDC-NH 2 displayed a lower detection limit (3.82 μM), higher stability (>180 days), and remarkable sensitivity (308 μA mM −1 cm −2 ). Additionally, a molecular sieve effect for Ni-BDC-NH 2 led to a noteworthy anti-interference ability and the sensor displays a fast response time of 5.4 s towards glucose detection. These results indicate that the as-synthesized non-enzymatic glucose sensor operates with a longer lifetime and is viable for use as an intensive monitoring system.

Zn–Co Bimetallic Zeolitic Imidazolate Frameworks as Nonenzymatic Electrochemical Glucose Sensors with Enhanced Sensitivity and Chemical Stability

Zn–Co Bimetallic Zeolitic Imidazolate Frameworks as Nonenzymatic Electrochemical Glucose Sensors with Enhanced Sensitivity and Chemical Stability