The Research On Electrochemical Sensor Based On Two Types Of New Composite Materials

Using new materials such as nanomaterials, in construction of highly sensitive and selective electrochemical sensors in order to improve the analysis performance and expand the application range has already been a hot issue of modern electroanalytical chemistry study. In this paper, two types of non-enzymatic glucose sensor and a hydrogen peroxide sensor were prepared based on new materials such as copper nanoparticles and brushite. The electrochemical methods such as cyclic voltammetry, differential pulse voltammetry and chronoamperometry were adopted to investigate their performances. This study provided new ideas to explore the nano-composite materials in the application of electrochemical sensors, had some guidance significances to develop novel enzyme immobilization methods. This thesis was divided into three chapters, the main contents including the following:1. The electrochemical sensor and its research progress were reviewed with 121 references.2. A novel non-enzymatic sensor for glucose based on ionic liquid (IL) as a binder combining copper nanoparticles (Cu NPs) with multiwalled carbon nanotubes (MWNTs) was developed and its electrochemical behaviors of glucose oxidation had been investigated. The results showed that the sensor had a good linear dependence on the glucose concentration in the range of 3.0×10-6 to 2.0×10-3 mol·L-1 (r=0.9959) with a sensitivity of 102.3μA mM-1, the detection limit was 9.3×10-7 mol·L-1 (S/N=3), and the sensor reached 95% of the steady-state current within 3s. The study might provide reference for the fabrication of non-enzymatic sensors for other carbohydrates.3. A novel non-enzymatic sensor for glucose based on copper nanoparticles/ polyaniline/multi-walled carbon nanotubes composites modified glassy carbon electrode was prepared by electrochemical method. A new method for glucose determination was established. The results showed that the sensor had good linear relationship with the glucose concentration in the range of 5.0×10-7～2.0×10-3 mol·L-1 (r=0.9955) with a high sensitivity of 134.6μA mM-1, and the detection limit was 1.9×10-7 mol·L-1 (S/N=3), the response time was shorter than 2 s. This study could provide a new idea for rapid construction of highly sensitive non-enzyme sensors of glucose and other carbohydrates.4. A novel hydrogen peroxide biosensor was fabricated by electrodeposition of brushite film and encapsulated HRP on a Pt electrode simultaneously. The sensor showed a good linearity in the range of 2.0×10-5～5.7×10-4 mol·L-1 (r=0.9985) with a sensitivity of 3.57μA mM-1 and the detection limit of 6.67×10-6 mol·L-1 (S/N=3) for the detection of H2O2. The apparent Michaelis-Menten constant Km was 0.20 m mol·L-1. This method had the advantage such as simple, fast, easy to operate, providing a new way for the preparation of biosensors based on other biological molecules.