Micro-/Nanofabrication in Analytical Chemistry and Temperature Dependent Studies of Underpotential Deposition of Mercury(II) on Au(III)

Abstract

This dissertation studies three routes to fabricate micro-/nano-sized structures for the purpose of analytical chemistry and the underpotential deposition (UPD) of mercury(II) onto Au(111) electrodes. In Chapter 2, we have studied the temperature dependence of the underpotential deposition (UPD) of mercury(II) onto Au(111) electrodes from a series of electrolytes in which anion interactions could be varied from essentially zero (i.e., HClO4) to strongly interacting with either the Au(111) substrate (i.e., H2SO4) or with solution phase Hg2+ ions (i.e., HC2H3O2). Both isothermal and non-isothermal cells were used to make temperature dependent cyclic voltammetry measurements. In Chapter 3, the two-component mixed self-assembled monolayers consisting of 4-aminothiophenol (4-ATP) and n-decanethiol (DT) were studied and the random arrays of polyaniline nano-/microelectrodes were fabricated based on the mixed SAMs. The features of the polyaniline nano-/microelectrodes were characterized and compared with theoretical results. A biosensor using the SAM-based polyaniline electrodes was tested and the preliminary results were discussed. In Chapter 4, the nanosphere lithography combined with electrochemical deposition is demonstrated to be a powerful technique that is able to produce inexpensive parallel nanostructures with fine resolution. Several nanostructures including pores, particles and rings were made through nanosphere lithography templates. A process of growing the pore film was given based on the AFM analysis. The pore size of the film could be controlled by the sphere size and the condition of electrochemical deposition. In Chapter 5, the connection of copper, silver and semiconductor CdSe microwires between anode and cathode was created through electrochemical deposition. The electrochemical reactions were studied. The semiconductor microwire has the potential of being applied in the detection of biomolecules