Non-enzyme Glucose Photochemical Sensor Research Based On The Au/Ag Nanoparticles

At present, diabetes has become a recognized health problem worldwide, with the improvement of living standards, the incidence of diabetes is in increase year by year, and it has attracted wide attention and research. Diabetes cause great harm to people’s health, for example,it can hurt the kidney, cardiovascular and peripheral vascular, also it has effect on metabolism, therefore, it is very important and urgent to detect the blood glucose in human body. Nanometer materials have large specific surface area and good biological compatibility, which have been widely applied in the field of glucose sensors. Nanometer materials such as nanometallic nanoparticles, nanowires, nanotubes, metal alloy nanoparticles shows good catalytic properties in glucose detection. The glucose sensor modified with nano materials shows high sensitivity, high selectivity, low detection limit and high stability.In the second chapter, Au and Ag NPs were synthesized by using sodium borohydride reduction method. Small Au NPs(~4 nm) can act as glucose oxidase(GOD) mimic enzyme to catalytically oxidize glucose in the presence of oxygen, producing gluconic acid and hydrogen peroxide, furthermore the generated hydrogen peroxide dissolved Ag NPs to lead the UV absorbance change of Ag NPs, which can realize the indirect measurement of glucose.In the experiments,we also discussed the influence of the catalyst concentration, temperature, p H value and reaction time. Results showed that the concertration of glucose between 5 μM to 70 μM had good linear, the correlation coefficient was 0.997, the lowest detection limit of this method could reach 3 μM. This method had high sensitivity, good selectivity, and could be used for the determination of the actual amounts of glucose in the blood.In the third part, triangular silver nanoparticles(Ag TNPs) were used instead of the spherical silver nanoparticles. First we investigated the reaction of Ag TNPs with hydrogen peroxide. Then Au NPs act as glucose oxidase(GOD) mimic enzyme to catalytically oxidize glucose, generating hydrogen peroxide, which reacted with Ag TNPs. It provided a method of determination of glucose. In this approach, hydrogen peroxide corrosion the three angle of Ag TNPs, leading to an obvious blue shift of ultraviolet absorption peak peak position, and the sensitivity was higher than that in second part. The linear range of this method is 0.5μM-30μM, the linear correlation coefficient and detection limit are founded to be 0.997 and 0.2μM has a lower detection limit.