Preparation Of Nanostractured Electrodes For Nou-enzymatic Glucose Sensors

Recently, with the rapid increase of diabetic, there is an urgent demand for developing a fast and accurate device to detect the blood glucose. Non-enzymatic glucose sensors have attracted considerable attention due to its efficient glucose sensing which are free from pH, temperature, limited stability, and high cost. Besides, non-enzymatic glucose sensors also play an important role in the fields of environment monitoring, biotechnology, food industry, biology fermentation and national defense construction. Therefore, developing a non-enzymatic glucose sensor with high sensitivity, good selectivity and wide linear range has important scientific significance and practical application value.Nanomaterials can strikingly increase the performance of non-enzymatic glucose sensors because of its excellent intrinsic properties, such as high catalytic activity, large specific surface area and good biological compatibility. Thus, in this paper, we prepared several kinds of electrodes based on nanomaterials for non-enzymatic glucose sensors. The crystal structure and morphology of the nanomaterials were analyzed by using a variety of characterization methods. The performance of non-enzymatic glucose sensing was systematically investigated by electrochemistry and photoelectrochemical methods. The main details are as follows:1. Reticular-vein-like Cu@Cu20/rG0 nanocomposites have been synthesized by direct redox reaction of Cu and graphene oxide (GO) through a hydrothermal method where the macropore Cu sheets served as the precursor of reticular-vein-like Cu2O as well as the reducing agent of GO. The results reveal that the reticular-vein-like Cu@Cu2O nanocomposites are homogeneously anchored onto rGO and act like the skeleton supporting the rGO sheets to avoid its aggregation or stacking. Electrochemical tests show that the Cu@Cu2O/rGO electrode exhibits remarkable electrocatalytic activity towards glucose oxidation, including a wide linear range, high sensitivity, good selectivity, low detection limit, good stability and reproducibility. In addition, the electrode presents comparable application with a commercial glucose oxidase (GOD)-based sensor. All these results suggest that the reticular-vein-like Cu@Cu20/rG0 modified electrode could be potentially applied for the construction of a non-enzymatic sensor.2. A novel photoelectrochemical (PEC) biosensing platform was constructed based on a ternary hybrid Ni/CdS/TiO2 nanotube array electrode, which was fabricated by the combination of electrochemical anodization and electrodeposition. The results reveal that the CdS and Ni nanoparticles were homogeneously dispersed on the TiO2 nanotube arrays. Here, the Ni nanoparticles on the surface of CdS/TiO2 heterojunctions play a dual role in enhancing the performance of the PEC biosensor. First, Ni nanoparticles serve as a hole receptor, which can promote the fast charge separation and act as a protective layer that improves the stability of the Ni/CdS/TiO2 electrode. Second, Ni can remarkably improve the photoelectrochemical performance because it is a highly efficient electrocatalyst. As a result, the Ni/CdS/TiO2 NTA electrode exhibits excellent PEC biosensing performance for the detection of glucose, including a wide linear range, a low detection limit, high sensitivity and good selectivity and stability. Therefore, the Ni/CdS/TiO2 nanotube arrays open a new avenue for the construction of high performance photoelectrochemical biosensors.3.3D Ni3S2 nanosheet arrays grown on Ni foam were successfully synthesized through a facile one-step hydrothermal approach and then directly applied as the electrode for non-enzymatic glucose sensor and supercapacitor. The results reveal that the 3D Ni3S2 nanosheet array electrode endows with fast ion and electron transport, a large electroactive surface area, and excellent structural stability. As a result, superior pseudocapacitive performance is achieved. Moreover, the Ni3S2 nanosheet array electrode also exhibits remarkable electrocatalytic activity towards glucose, including high sensitivity, good selectivity, a low detection limit and a rapid response. All these impressive measures of performance suggest that the Ni3S2 nanosheet array is a promising electrode material for supercapacitors and non-enzymatic glucose sensors.