Investigation Of Glucose Electrochemical Sensors Based On Ni-based Nanocomposites

With the development of nanotechnology the nanoparticles attract substantial interest for they exhibit unique catalytic properties. Therefore, they have unique application value in the field of non-enzyme electrochemical and biological sensors and have been employed for construction of various electrochemical sensors. In this paper, three novel nickel-based nanocomposites which own different morphology and structure were synthesized using different chemical methods, and three electrochemical glucose sensors with excellent overall performance based on these materials had set up. Then, the morphology, structure, electrochemical properties of nanocomposites and inherent association between them had studied by experiments, which lay the foundation for a new method of glucose analyzing and detecting. This thesis not only made the study of electrochemical sensing icing on the cake, but also opened up a vast world of nickel-based nanomaterials in applications. The thesis consists of four chapters, the main contents are divided into the following three parts:1. A new method of detecting glucose based on Ni/NiCo-LDHs which synthesized by multiple hydrothermal was constructed. The experiment results showed better electrocatalytic towards oxidation of glucose after NiCo-LDHs nanomaterials have been partially reduced. The sensor had a low detection limit which was 1.6 ?mol·L^-1 ?S/N=3?, existed two linearly ranges of 5.0 ?mol·L^-1?1.2 mmol·L^-1 and 1.2?15 mmol·L^-1, the corresponding sensitivity was 423.1 ?A·(mmol·L^-1)?-1?·cm^-2 and 1235.0 ?A(mmol·L^-1)?-1?·cm^-2, respectively. This research provides a new idea for electrochemical sensing based on nickel-based hydrotalcite nanocomposites.2. Ni?OH?₂/Au nanocomposites were formed by dispersing Ni?OH?₂ nanoparticles into Au nanoparticle suspension evenly and electrostatically self-assembled, which were used to fabricating non-enzyme glucose sensor. The electrochemical properties of the sensor were explored by cyclic voltammetry and amperometry. The investigation showed that the Ni?OH?₂/Au nanohybrid film at the sensor exhibited a high electrocatalytic activity towards electrooxidation of glucose; and under the optimal conditions, the linear ranges of glucose were from 5.0 ?mol·L^-1 to 2.2 mmol·L^-1 with a low detection limit of 0.92 ?mol·L^-1 ?S/N=3? and high sensitivity of 371.2 ?A·(mmol·L^-1)?-1?·cm^-2.3. A new core-shell structure nanocomposite of NiO@PPy/Au was synthesized bychemical method and be used to modifing the bare GCE. The modified electrode showed excellent electrochemical activity toward the oxidation of glucose. At the optimum conditions, the calibration curve for glucose determination was linear in the range of 0.5 ?mol·L^-1?1.7 mmol·L^-1 and high sensitivity of 802.9 ?A·(mmol·L^-1)?-1?·cm^-2 a low detection limit ?S/N=3? of 0.15 ?mol·L^-1. Compared with other glucose sensor of this thesis, the core-shell nanocomposite NiO@PPy study synthesized owned unique topographythis; and the linear range of the sensor configuration was widest, set up to four orders of magnitude. While the new nanostructures can provide a reference for the design and synthesis of nanocomposites.