L-glutamate plays a vital role in central nervous system. It is a neurotransmitterassociated with several neurological disorders like Parkinson's disease, epilepsyand stroke. Continuous and fast monitoring of this neurotransmitter has become amajor concern for neuroscientists throughout the world. A simple, sensitive, and reliable L-glutamate microsensor with short responsetime has been developed using ceramic-based microelectrode arrays with platinum recording sites. The electrodes were modified by electrodeposition of Platinum black (Pt-black) to detect hydrogen peroxide (H2O2) which was produced by enzymatic reactions of glutamate oxidase immobilized on the electrode surface. Modification of Pt electrodes with Pt-black has been adoptedbecause the microscale roughness of Pt-black increases the effective surface area of the electrode and promotes efficiency of H2O2 electro-oxidation. The modified Pt recording sites were coated with m-phenylenediamine (mPD) and L-glutamate oxidase (L-GluOx). mPD acts as an barrier for extracellular interferents such as ascorbic acid and dopamine, thus increasing the selectivity of electrode for Glutamate (Glu). This modified microsensor was highly sensitive to H2O2(686.3??156.48 ??AmM-1cm-2), and Glutamate (492.2??112.67 ??AmM-1cm-2) at 700mV versus Ag/AgCl reference. Deposition of Pt nano-particles on recording sites enhanced the sensitivity to H2O2 by 2 times and the sensitivity to glutamate by 1.5 times.

Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 208-222).

The behavior of adsorbed carbon monoxide on platinum was studied using potential difference infrared spectroscopy. Three solvents and three electrolytes were chosen, and data gathered at both high and low adsorbate coverages. The rate of change of IR peak position with applied potential, the Stark tuning rate, was used as an indicator of the local electric field strength at the interface. It was determined that neither solvated cation size nor bulk dielectric constant accounts for the changes in Stark tuning rate with different solvents. / Master of Science