Non‐enzymatic Fructose Sensor Based on Co3O4 Thin Film

In this study, we report on the selective of fructose on Co₃O₄ thin film electrode surface. A facile chemical solution deposition technique was used to fabricate Co₃O₄ thin film on fluorine doped tin oxide, FTO, glass. Electrode characterization was done using XRD, HRTEM, SEM, AFM, and EIS. The constructed sensor exhibited two distinctive linear ranges (0.021–1.74 mM; 1.74–∼15 mM) covering a wide linear range of up to ∼15 mM at an applied potential of +0.6 V vs Ag/AgCl in 0.1 M NaOH solution. The sensor demonstrated high, reproducible and repeatable (R.S.D of <5 %) sensitivity of 495 (lower concentration range) & 53 (higher concentration range) μA cm⁻² mM⁻¹. The sensor produced a low detection limit of ∼1.7 μM (S/N =3). The electrode was characterised by a fast response time of <6 s and long term stability. The repeatability and stability of the electrode resulted from the chemical stability of Co₃O₄ thin film. The sensor was highly selective towards fructose compared to the presence of other key interferences i. e. AA, AC, UA. The ease of the electrode fabrication coupled with good electrochemical activity makes Co₃O₄ thin film, a promising candidate for non‐enzymatic fructose detection.     

Binderless Solution Processed Zn Doped Co3O4 Film on FTO for Rapid and Selective Non‐enzymatic Glucose Detection

A simple solution based deposition process has been used to fabricate Zn doped Co₃O₄ electrode as an electrocatalyst for non‐enzymatic oxidation of glucose. XRD, HRTEM, SEM, EELS, AFM, EIS was used to characterise the electrode. The addition of Zn as dopant on Co₃O₄ resulted in enhanced electrochemical performance of Zn:Co₃O₄ material compared to pristine Co₃O₄ due to increased charge transferability. The as prepared electrode showed fast response (<7 s) time, good sensitivity (193 μA mM⁻¹ cm⁻²) in the linear range of 5 μM–0.62 mM, good selectivity towards glucose at a relatively lower applied potential of +0.52 V in 0.1 M NaOH solution. A detection limit of ∼2 μM was measured for the Zn:Co₃O₄ electrode. The applied fabrication method resulted in good inter and intra electrode reproducibility as was shown by the lower relative standard deviation values (R.S.D). The electrode retained 70 % of initial current response after 30 days. Although the as prepared Zn:Co₃O₄ electrodes did not result in highest reported sensitivity, and lowest limit of detection; the ease of fabrication and scalability of production, good inter and intra electrode reproducibility makes it a potential candidate for commercial application as glucose sensor.     

Applying Co3O4@nanoporous Carbon to Nonenzymatic Glucose Biofuel Cell and Biosensor

A novel hierarchically nanoporous carbon (NPC) derived from Al‐based porous coordination polymer is prepared by two‐step carbonization method for immobilization of the Co₃O₄ in the application of the nonenzymatic biofuel cells and biosensors. The structure and morphology are characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), high‐resolution transmission electron microscopy (HRTEM), and X‐ray diffraction (XRD). Brunauer‐Emmett‐Teller (BET) is to characterize the porous nature of the NPC, and X‐ray photoelectron spectroscopy (XPS) is to characterize the composition of Co₃O₄@nanoporous carbon (Co₃O₄@NPC). Without collapse in the high carbonization temperature (above 1600 °C), the NPC maintains the nanoporous structure and high specific surface area of 1551.2 m² g⁻¹. In addition, the NPC is composited with Co₃O₄ by hydrothermal method to form the Co₃O₄@NPC. When tested as the nonenzymatic electrocatalyst for glucose oxidation reaction (GOR), the Co₃O₄@NPC exhibits higher response to glucose, in which the current shifts up by 64 %, than pure Co₃O₄ in 0.1 M KOH. The limit of detection is 0.005 mM (S/N=3) and response time is within 3 s. The detection range can be divided into two sections of 0.02–1.4 mM and 1.4–10.7 mM with the sensitivity of 249.1 μA mM⁻¹ cm⁻² and 66.6 μA mM⁻¹ cm⁻², respectively. A glucose fuel cell is constructed with the Co₃O₄@NPC as the anode and Pt/C catalyst as the cathode. The open‐circuit potential of the nonenzymatic glucose/O₂ fuel cell was 0.68 V, with a maximum power density of 0.52 mW cm⁻² at 0.27 V. This work may contribute to exploring other nanoporous carbons for application in glucose fuel cells and biosensors.     

A Novel Enzymatic Glucose Biosensor and Nonenzymatic Hydrogen Peroxide Sensor Based on (3‐Aminopropyl) Triethoxysilane Functionalized Reduced Graphene Oxide

In the present study, a novel enzymatic glucose biosensor using glucose oxidase (GOx) immobilized into (3‐aminopropyl) triethoxysilane (APTES) functionalized reduced graphene oxide (rGO‐APTES) and hydrogen peroxide sensor based on rGO‐APTES modified glassy carbon (GC) electrode were fabricated. Nafion (Nf) was used as a protective membrane. For the characterization of the composites, Fourier transform infrared spectroscopy (FTIR), X‐ray powder diffractometer (XRD), and transmission electron microscopy (TEM) were used. The electrochemical properties of the modified electrodes were investigated using electrochemical impedance spectroscopy, cyclic voltammetry, and amperometry. The resulting Nf/rGO‐APTES/GOx/GC and Nf/rGO‐APTES/GC composites showed good electrocatalytical activity toward glucose and H₂O₂, respectively. The Nf/rGO‐APTES/GC electrode exhibited a linear range of H₂O₂ concentration from 0.05 to 15.25 mM with a detection limit (LOD) of 0.017 mM and sensitivity of 124.87 μA mM⁻¹ cm⁻². The Nf/rGO‐APTES/GOx/GC electrode showed a linear range of glucose from 0.02 to 4.340 mM with a LOD of 9 μM and sensitivity of 75.26 μA mM⁻¹ cm⁻². Also, the sensor and biosensor had notable selectivity, repeatability, reproducibility, and storage stability.     

A Highly Sensitive and Selective Non-enzymatic Hydrogen Peroxide Sensor Based on Nanostructured Co3O4 Thin Films Using the Sol-gel Method

In this work we report an easy and efficient way to fabricate nanostructured cobalt oxide (Co₃O₄) thin films as a non-enzymatic sensor for H₂O₂ detection. Co₃O₄ thin films were grown on ITO glass substrates via the sol-gel method and characterized with several techniques including X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and optical absorbance. The Co₃O₄ thin films’ performance regarding hydrogen peroxide detection was studied in a 0.1 M NaOH solution using two techniques, cyclic voltammetry (CV) and amperometry. The films exhibited a high sensitivity of 1450 μA.mM⁻¹.cm⁻², a wide linear range from 0.05 μM to 1.1 mM, and a very low detection limit of 18 nM. Likewise, the Co₃O₄ thin films produced showed an exceptional stability and a high selectivity.     

α‐Fe2O3 Film with Highly Photoactivity for Non‐enzymatic Photoelectrochemical Detection of Glucose

A non‐enzyme photoelectrochemical (PEC) glucose sensor based on α‐Fe₂O₃ film is investigated. The α‐Fe₂O₃ film was fabricated via a simple spin coating method. The proposed glucose sensor exhibits good selectivity, a fast response time of <5 s, a linear range of 0.05 to 6.0 mM, sensitivity of 17.23 μA mM^?1 cm^?2 and a detection limit of 0.05 μM. Meanwhile, the excellent performances of the α‐Fe₂O₃ sensor were obtained in reproducibility and the long‐term stability under ambient condition. The linear amperometric response of the sensor covers the glucose levels in physiological and clinical for diabetic patients. Therefore, this non‐enzyme PEC sensor based on α‐Fe₂O₃ film has a great potential application in the development of glucose sensors.     

Facile Synthesis of Graphene/Cobalt Oxide Nanohexagons for the Selective Detection of Dopamine

This work presents a simple green approach for the chemical synthesis of cobalt oxide nano hexagons (Co₃O₄ NHs) with an average size of 160±40 nm incorporated graphene nanosheets (GR). The techniques used to confirm the formation of GR−Co₃O₄ NHs are transmission electron microscopy (TEM), energy‐dispersive X‐ray spectroscopy (EDX), and X‐ray diffraction spectroscopy (XRD). The dopamine (DA) sensor was fabricated by drop casting GR−Co₃O₄ NHs on the pre‐cleaned glassy carbon electrode (GCE). GR−Co₃O₄ modified GCE displayed a sensitive and selective electrochemical determination of DA compared to only GR and Co₃O₄ NHs modified GCE. Our fabricated sensor showed a wide linear range from 0.2 to 3443 μM with low limit of detection (84 nM) towards the determination of DA. The sensitivity of our fabricated sensor was calculated to be 108 μA mM⁻¹ cm⁻². As well, a significant storage stability, repeatability and reproducibility were attained by GR−Co₃O₄ NHs modified GCE. Human urine samples were targeted for the demonstration of practicality of our sensor.     

A Facile Chemical Synthesis of Cu2O Nanocubes Covered with Co3O4 Nanohexagons for the Sensitive Detection of Glucose

Copper (I) oxide nanocubes (Cu₂O NCs) covered with cobalt oxide nanohexagons (Co₃O₄ NHs) were prepared through simple chemical method. Here, ascorbic acid is used as reducing and capping agent for the synthesis of nanocubes and nanohexagons. Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), Energy‐dispersive X‐ray spectroscopy (EDX) and X‐ray diffraction spectroscopy (XRD) were employed to confirm the prepared nanocomposite. Cu₂O NCs?Co₃O₄ NHs nanocomposite is drop cast on the glassy carbon electrode (GCE) for the fabrication of glucose sensor. The fabricated Cu₂O NCs?Co₃O₄ NHs/GCE exhibited a better electrocatalytic activity towards the determination of glucose than that of individually fabricated Cu₂O NCs and Co₃O₄ NHs modified GCE. Our finding exhibited a wide linear range from 1 μM to 5330 μM with LOD of 0.63 towards glucose. In addition, the sensor attained appreciable stability, repeatability and reproducibility. Practicality of the sensor was demonstrated in human serum samples. The main advantages of the fabricated sensor are simple, biocompatible, cost effective, fast response and highly stable electrode surface.     

Nitrogen‐doped Hollow Co3O4 Nanofibers for both Solid‐state pH Sensing and Improved Non‐enzymatic Glucose Sensing

Nitrogen‐doped hollow cobalt oxide nanofibers (Co₃O₄ NFs) with both glucose catalytic activity and pH sensitivity were fabricated through core‐sheath electrospinning technique, followed by calcination. The as‐developed nitrogen‐doped hollow Co₃O₄ NFs were thoroughly characterized using various techniques, and then employed to fabricate a dual electrochemical sensor for both pH sensing and glucose sensing. The pH sensitivity of the developed nitrogen‐doped hollow Co₃O₄ NFs demonstrated a Nernst constant of 12.9–15.9 mV/pH in the pH range of 3.0～9.0 and 6.8–10.7 mV/pH in the pH range of 9.0～13.0, respectively. The developed hollow cobalt oxides nanofibers sensor also possesses glucose sensitivity of 87.67 μA mM^?1 cm^?2, the limit of detection of 0.38 μM (S/N=3), and an acceptable selectivity against several common interferents in non‐enzymatic glucose determination. High accuracy for monitoring glucose in human serum sample was also demonstrated. These features indicate that the as‐synthesized nitrogen‐doped hollow cobalt oxides nanofibers hold great potential in the development of a unique dual sensor for both solid‐state pH sensing and superior non‐enzymatic glucose sensing.     

MOF‐Derived Spinel NiCo2O4 Hollow Nanocages for the Construction of Non‐enzymatic Electrochemical Glucose Sensor

Non‐enzymatic glucose sensor is greatly expected to take over its enzymatic counterpart in the future. In this paper, we reported on a facile strategy to construct a non‐enzymatic glucose sensor by use of NiCo₂O₄ hollow nanocages (NiCo₂O₄ HNCs) as catalyst, which was derived from Co‐based zeolite imidazole frame (ZIF‐67). The NiCo₂O₄ HNCs modified glassy carbon electrode (NiCo₂O₄ HNCs/GCE), the key component of the glucose sensor, showed highly electrochemical catalytic activity towards the oxidation of glucose in alkaline media. As a result, the proposed non‐enzymatic glucose sensor afforded excellent analytical performances assessed with the aid of cyclic voltammetry and amperometry (i–t). A wide linear range spanning from 0.18 μΜ to 5.1 mM was achieved at the NiCo₂O₄ HNCs/GCE with a high sensitivity of 1306 μA mM^?1 cm^?2 and a fast response time of 1 s. The calculated limit of detection (LOD) of the sensor was as low as 27 nM (S/N=3). Furthermore, it was demonstrated that the non‐enzymatic glucose sensor showed considerable anti‐interference ability and excellent stability. The practical application of the sensor was also evaluated by determination of glucose levels in real serum samples.     

Fabrication of Hierarchically Structured MOF‐Co3O4 on Well‐aligned CuO Nanowire with an Enhanced Electrocatalytic Property

Engineering appropriate shape and size of three‐dimensional inorganic nanostructures materials is of one the main critical problems in pursuing high‐performance electrode materials. Herein, we fabricate a metal‐organic framework derived cobalt oxide (Co₃O₄) are grown on copper oxide nanowire (CuO NWs) supported on the surface of 3D copper foam substrate. The highly aligned CuO NWs were prepared by using electrochemical anodization of copper foam in ambient temperature and followed by MOF Co₃O₄ was grown via a simple in situ solution deposition then consequent calcination process. The obtained binder‐free 3D CuO NWs@Co₃O₄ nanostructures were further characterized by using X‐ray diffraction, X‐ray photoelectron spectroscopy, field‐emission scanning electron microscopy, and transmission electron microscopy. Furthermore, electrochemical sensing of glucose was studied by using Cyclic Voltammetry, and chronoamperometry techniques. Interestingly, 3D CuO NWs@Co₃O₄ electrode exhibits excellent performance for the oxidation of glucose compared with individual entities. The proposed sensor shows wide linear ranges from 0.5 μM to 0.1 mM with the sensitivity of 6082 μA/μM and the lowest detection limit (LOD) of 0.23 μM was observed with the signal to noise ratio, (S/N) of 3. The superior catalytic oxidation of glucose mainly is endorsed by the excellent electrical conductivity and synergistic effect of the Co₃O₄ and CuO NWs.     

The Hybrid of Gold Nanoparticles and 3D Flower‐like MnO2 Nanostructure with Enhanced Activity for Detection of Hydrogen Peroxide

3D Flower‐like manganese dioxide (MnO₂) nanostructure with the ability of catalysis for hydrogen peroxide (H₂O₂) and super large area that can support gold nanoparticles (AuNPs) with enhanced activity of electron transfer have been developed. The nanostructure of hybrids was prepared by directly mixing citric‐capped AuNPs and 3‐aminopropyltriethoxysilane (3‐APTES)‐capped nano‐MnO₂ using an electrostatic adsorption strategy. The Au‐MnO₂ composite was extensively characterized by scanning electron microscope (SEM), X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), the Brunauer‐Emmett‐Teller (BET) method and X‐ray photoemission spectroscopy (XPS). Electrochemical properties were evaluated through cyclic voltammetry (CV) and amperometric method. The prepared sensor showed excellent electrochemical properties towards H₂O₂ with a wide linear range from 2.5×10⁻³∼1.39 mM and 3.89∼13.89 mM. The detection limit is 0.34 μM (S/N=3) with the sensitivities of 169.43 μA mM⁻¹ cm⁻² and 55.72 μA mM⁻¹ cm⁻². The detection of real samples was also studied. The result exhibited that the prepared sensor can be used for H₂O₂ detection in real samples.     

Real‐time Selective Detection of Hydrogen Peroxide Based on a Tantalum Deposited Pencil Lead Electrode for Evaluation of Enzyme Activities

In this study, we have carried out electrodeposition of tantalum (Ta) nanostructures on pencil lead electrode in non‐aqueous media at room temperature by applying a constant potential. The deposited Ta on pencil lead was examined for the catalytic effect regarding hydrogen peroxide (H₂O₂) reduction with voltammetry and amperometry. Ta/pencil lead electrode exhibited amperometric sensitivity of 0.317 μA mM⁻¹ cm⁻² and fast response time of 0.75 s, where selective detection of H₂O₂ was fulfilled without interruption from common electroactive biomaterials such as O₂, uric acid, ascorbic acid, dopamine, acetamidophenol, and glucose. For practical applications, the dynamic concentration changes of H₂O₂ during catalase and glucose oxidase‐involved reactions, either eliminating or producing H₂O₂, were successfully traced in real time with as‐prepared electrode. From the kinetics study for catalase and glucose oxidase, we evaluated Michaelis constants (K _m^app) as 7.8 mM for catalase and 37 mM for glucose oxidase, respectively.     

Synthesis of Co0.5Mn0.1Ni0.4C2O4⋅n H2O Micropolyhedrons: Multimetal Synergy for High‐Performance Glucose Oxidation Catalysis

Owing to the synergy between metals, trimetal oxalate micropolyhedrons have been synthesized by means of a room‐temperature coprecipitation strategy. The effect of their nanoscale size on their electrochemical performance toward glucose oxidation was investigated. In particular, the Co_0.5Mn_0.1Ni_0.4C₂O₄?n H₂O micropolyhedrons illustrated prominent electrocatalytic activity for the glucose oxidation reaction. Additionally, the Co_0.5Mn_0.1Ni_0.4C₂O₄?n H₂O micropolyhedrons, when used as an electrode material, illustrated an excellent lower limit of detection (1.5 μm ), a wide detection concentration range (0.5–5065.5 μm ), and a high sensitivity (493.5 μA mm ^?1 cm^?2). Further analysis indicated that the effectively improved conductivity may have been due to the small size of the materials, and it was easier to form a flat film when Nafion was coated onto the glassy carbon electrode.     

A Fe3O4‐Based Chemical Sensor for Cathodic Determination of Hydrogen Peroxide

A new cathodic scheme for hydrogen peroxide (H₂O₂) measurement by Fe₃O₄‐based chemical sensor was described. The unique characteristic of electrocatalytic property was firstly investigated by voltammetry. And then the amperometric response of H₂O₂ was measured at ?0.2 V (vs. Ag/AgCl) by Fe₃O₄ modified glassy carbon rotating disk electrode. The kinetic parameter was also calculated from Koutecky‐Levich plot, and the value was 6.4×10^?4 cm s^?1 in pH 3 citrate buffer. In order to benefit the possible biomedical applications, Fe₃O₄/chitosan modified electrode was also investigated in this experiment. There were several characteristic enhancements by the coated chitosan thin film for H₂O₂ sensor. The calibration curves were found to be linear up to 4.0 and 5.0 mM (r=0.999) in pH 3 and 7 with the detection limits of 7.6 and 7.4 μM L^?1 (S/N=3). The stability was evaluated by the results of half‐life time (t_50%) for 9 months at room temperature and 24 months at 4 °C.     

Assessment of Melamine in Different Water Samples with ZnO-doped Co3O4 Nanoparticles on a Glassy Carbon Electrode by Differential Pulse Voltammetry

In this investigation, a melamine electrochemical sensor has been developed by using wet-chemically synthesized low-dimensional aggregated nanoparticles (NPs) of ZnO-doped Co₃O₄ as sensing substrate that were decorated onto flat glassy carbon electrode (GCE). The characterization of NPs such as UV-Vis, FTIR, XRD, XPS, EDS, and FESEM was done for detailed investigations in optical, functional, structural, elemental, and morphological analyses. The ZnO-doped Co₃O₄ NPs decorated GCE was used as a sensing probe to analyze the target chemical melamine in a phosphate buffer at pH 5.7 by applying differential pulse voltammetry (DPV). It exhibited good performances in terms of sensor analytical parameters such as large linear dynamic range (LDR; 0.15–1.35 mM) of melamine detection, high sensitivity (80.6 μA mM⁻¹ cm⁻²), low limit of detection (LOD; 0.118±0.005 mM), low limit of quantification (LOQ; 0.393 mM), and fast response time (30 s). Besides this, the good reproducibility (in several hours) and repeatability were investigated under identical conditions. Moreover, it was implemented to measure the long-time stability, electron mobility, less charge-transfer resistance, and analyzed diffusion-controlled process for the oxidation reaction of the NPs assembled working GCE electrode, which showed outstanding chemical sensor performances. For validation, real environmental samples were collected from various water sources and investigated successfully with regard to the reliability of the selective melamine detection with prepared NPs coated sensor probe. Therefore, this approach might be introduced as an alternative route in the sensor technology to detect selectively unsafe chemicals by an electrochemical method with nanostructure-doped materials for the safety of environmental, ecological, healthcare fields in a broad scale.     

Immobilized Fullerene C60‐Enzyme‐Based Electrochemical Glucose Sensor

A mixed‐valence cluster of cobalt(II) hexacyanoferrate and fullerene C60‐enzyme‐based electrochemical glucose sensor was developed. A water insoluble fullerene C60‐glucose oxidase (C60‐GOD) was prepared and applied as an immobilized enzyme on a glassy carbon electrode with cobalt(II) hexacyanoferrate for analysis of glucose. The glucose in 0.1 M KCl/phosphate buffer solution at pH = 6 was measured with an applied electrode potential at 0.0 mV (vs Ag/AgCl reference electrode). The C60‐GOD‐based electrochemical glucose sensor exhibited efficient electro‐catalytic activity toward the liberated hydrogen peroxide and allowed cathodic detection of glucose. The C60‐GOD electrochemical glucose sensor also showed quite good selectivity to glucose with no interference from easily oxidizable biospecies, e.g. uric acid, ascorbic acid, cysteine, tyrosine, acetaminophen and galactose. The current of H₂O₂ reduced by cobalt(II) hexacyanoferrate was found to be proportional to the concentration of glucose in aqueous solutions. The immobilized C60‐GOD enzyme‐based glucose sensor exhibited a good linear response up to 8 mM glucose with a sensitivity of 5.60 × 10² nA/mM and a quite short response time of 5 sec. The C60‐GOD‐based glucose sensor also showed a good sensitivity with a detection limit of 1.6 × 10^‐6 M and a high reproducibility with a relative standard deviation (RSD) of 4.26%. Effects of pH and temperature on the responses of the immobilized C60‐GOD/cobalt(II) hexacyanoferrate‐based electrochemical glucose sensor were also studied and discussed.     

A Novel Biomimetic Hydrogen Peroxide Biosensor Based on Pt Flowers‐decorated Fe3O4/Graphene Nanocomposite

A sensitive and selective amperometric H₂O₂ biosensor was obtained by utilizing the electrodeposition of Pt flowers on iron oxide‐reduced graphene oxide (Fe₃O₄/rGO) nanocomposite modified glassy carbon electrode (GCE). The morphology of Fe₃O₄/rGO and Pt/Fe₃O₄/rGO was characterized by transmission electron microscopy (TEM) and scanning electron microscopy (SEM), respectively. The step‐wise modification and the electrochemical characteristics of the resulting biosensor were characterized by cyclic voltammetry (CV) and chronoamperometry methods. Thanks to the fast electron transfer at the Pt/Fe₃O₄/rGO electrode interface, the developed biosensor exhibits a fast and linear amperometric response upon H₂O₂. The linear range of Pt/Fe₃O₄/rGO is 0.1∼2.4 mM (R²=0.998), with a sensitivity of 6.875 μA/mM and a detection limit of 1.58 μM (S/N=3). In addition, the prepared biosensor also provides good anti‐interferent ability and long‐term stability due to the favorable biocompatibility of the electrode interface. The proposed sensor will become a reliable and effective tool for monitoring and sensing the H₂O₂ in complicate environment.     

Synthesis of PtxSn/MWCNTs and their Application in Non‐enzymatic Glucose and Hydrogen Peroxide Sensors

Pt_xSn/MWCNTs (x=1, 2, 3) nanocomposites were synthesized by chemical reduction. Comparing all of the materials, the results revealed that the best material was Pt₃Sn/MWCNTs. The sensor based on Pt₃Sn/MWCNTs exhibited excellent catalytic activities towards glucose and hydrogen peroxide. Sensing of glucose had a double‐linear range: one was between 50 μM and 550 μM, the other was between 1.35 mM and 16.35 mM. These were due to the fact that more and more intermediate species were adsorbed onto the electrode surface with increasing concentration of glucose, which limited the following glucose oxidation. Meanwhile, the sensor also had a linear response range between 0.05 mM and 18.95 mM for hydrogen peroxide. Furthermore, the glucose and hydrogen peroxide sensors exhibited excellent selectivity, stability, and reproducibility. Thus the sensors had potential utilities in the detection of glucose and hydrogen peroxide.     

Embedment of Well Dispersed Nickel Nanoparticles in Sulfonate and Benzimidazole Functionalized Poly (Arylene Ether Ketone) Film for the Electrocatalytic Oxidation of Glucose

Stable and well dispersed nickel nanoparticles (NiNPs) were fabricated and embedded in a novel polymer sulfonate and benzimidazole functionalized poly (arylene ether ketone) (S‐BI‐PAEK) film. After drop‐casting the mixed solution of S‐BI‐PAEK and NiSO₄ on glassy carbon electrode (GCE) surface, the uniformly distributed NiNPs were formed and stably embedded in S‐BI‐PAEK film by in‐situ electrochemical reduction method. The embedment and well dispersity of NiNPs in S‐BI‐PAEK film was probably attributed to the strong chelation of sulfonate and benzimidazole functional groups contained in S‐BI‐PAEK toward Ni²⁺ ions, as well as the transferability of Ni²⁺ ions in S‐BI‐PAEK film. The NiNPs/S‐BI‐PAEK composite film was characterized by scanning electron microscopy (SEM), energy dispersive X‐ray spectroscopy (EDS), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). It exhibited good electrocatalytic activity toward glucose oxidation in 0.1 mol L⁻¹ NaOH solution with high stability. The NiNPs/S‐BI‐PAEK/GCE showed a fast amperometric response with a wide linear range from 1 μM to 4 mM and a low detection limit of 200 nmol L⁻¹ (S/N=3) for the determination of glucose by amperometry at a potential of 0.55 V. Finally it was successfully employed to determine glucose in human serum. Therefore, the novel fabrication method of nickel nanoparticles was promising for the future development of non‐enzymatic glucose sensor.