Title

Synthesis of (Nano)fibers via Electrospinning and Their Application in Electrochemical Sensors

Date of Completion

January 2011

Keywords

Engineering, Chemical|Engineering, Materials Science

Degree

Ph.D.

Abstract

This Ph.D. project aims at developing novel electrochemical sensors for fast, sensitive, selective, reproducible, stable and cost-effective detection of glucose, hydrazine and H2O2, which are of paramount importance to environmental monitoring and clinical diagnostics. The main objective of this research is to fabricate novel functionalized (nano)fibers via electrospinning and then explore their application in the development of enhanced electrochemical sensors, with major effort focusing on nonenzymatic glucose sensors. Co3O4 and NiO nanofibers were firstly successfully prepared and investigated for glucose detection. The mechanism for enhanced glucose detection and excellent anti-interference property were discussed. In order to further improve the glucose sensing performance, noble metals (including Ag, Au and Pt) and a conducting metal oxide, CdO, were incorporated into NiO nanofibers which have good glucose electrocatalytic capability and better anti-interference property than Co3O4 nanofibers. The noble metals-doped NiO nanofibers showed a synergistic effect towards glucose oxidation, which greatly improved the glucose sensing performance, with lower onset potential, lower detection limit and higher sensitivity. Moreover, our study indicated the CdO incorporation can greatly enhance the conductivity of NiO nanofibers. The dislocated NiO-CdO hybrid nanofibers showed even higher sensitivity towards glucose electrooxidation than those of noble metals-doped NiO, suggesting that CdO was a good substitute for noble metals. In addition, the applications of the novel functionalized nanofibers in the sensitive and selective detection of hydrazine and H2O2 were also explored. Studies on Pt-doping in TiO2 nanofibers for hydrazine detection, SWNTs-doping in hemoglobin microbelts and Fe2O 3-doping in carbon nanofibers for H2O2 detection were also conducted and all showed enhanced sensing performance. These results reveal the great potential applications of electrospun fibers and the significance of the doping strategy achieved by the facile co-electrospinning technique in the development of electrochemical sensors. ^