Glucose Nonenzymatic Sensors Based On Nanomaterials

With the increasing number of the diabetics in the world, diabetes mellitus turns to be a global devil which makes great threatens to one’s healthy, and the rapid and reliable detection of blood sugars can guarantee the timely precaution and treatment of the disease. Thanks to these advantages including rapid response, high sensitivity, good selectivity, simple operation and low cost, electrochemical sensors have been widely used for monitoring blood sugars. In recent years, Pt-based alloys and graphene-functionalized materials have been demonstrated capable of catalyzing glucose, and the fabricated sensors can provide highly sensitive, selective and stable performance for glucose detection. In this thesis, we assembled three glucose electrochemical sensors using these materials, and the details are as follows:1. The Pt-Pd nanowire arrays were fabricated by electrodepositing Pt-Pd alloys into the pores of anodic aluminum oxide (AAO) templates and subsequently chemical etching the templates off. Pt-Pd nanowire arrays stand on the electrode substrate vertically, and the diameter is uniformly distributed, with the shape and diameter well agreed to that of the AAO pores. It is demonstrated that the Pt-Pd nanowire arrays show high catalytic activity for glucose oxidation and enzyme-free sensing, represent sensitivity of29.2μAcm-2mM-1, which due to their larger activity area and high catalyst utilization.2. Vertical Pt-Pd nanotube arrays were prepared by a one-step electrodeposition via porous AAO membranes as the hard template. By employing different deposition potentials, Pt-Pd NTAs were obtained. We assessed the catalytic performance of Pt-Pd NTAs towards glucoseelectro-oxidation in neutral media (0.1M PBS, pH7.4, containing0.1M Cl-1), with sensitivity of43.2μA cm-2mM-1. We demonstrated that the porous Pt-Pd architectures with a large surface area are able to provide higher catalytic activity for glucose electro-oxidation compared to the Pt-Pd nanowire arrays.3. We synthesized a hybrid material by growing CO3O4nanocrystals on reduced mildly oxidized graphene oxide (rmGO). and used it as a high-performance catalyst for glucose electro-oxidation and enzyme-free analysis. By dopinhg N into the hybrid, we further obtained the Co2O3/N-rmGO. The Co3O4/N-rmGO hybrid exhibits superior catalytic activity towards glucose oxidation in alkaline solutions. with high sensitivity of1118μA cm-2mM-1. Besides, the fabricated sensor shows high sensitivity and stablility for the specific determination of glucose.