Date of Award

5-2012

Document Type

Thesis

Degree Name

Master of Science (MS)

Legacy Department

Bioengineering

Advisor

Zhang, Guigen

Committee Member

Alexis , Frank

Committee Member

Tzeng , Jeremy

Abstract

The behavior of biological molecules such as proteins at the electrode/electrolyte has been of considerable interest for the development of biosensors. Several investigative techniques including Potentiometry, Voltammetry, Amperometry, and Electrochemical Impedance Spectroscopy are being employed to study and analyze these molecular surface interactions. Investigative techniques such as cyclic voltammetry involve the application of a large potential to probe the electrode characteristics and capture the bulk membranous events to obtain the required measurements. This study looks to achieve two major objectives through the use of a novel technique, namely, the double layer capacitive method: 1) to analyze the electrochemical behavior of proteins adsorbed on Gold and Platinum metal electrode surfaces and 2) to study the adsorption and electro oxidation of glucose on Platinum surfaces. The change in the double layer capacitance value that varies upon adsorption of proteins is measured as an electrode-electrolyte interface characteristic perturbation upon application of a small potential. Bovine serum albumin (BSA) was used as model protein with Gold and Platinum working electrode surfaces. Results indicate that capacitance measurement is a sensitive and cost-effective method to probe the molecular surface interactions and can be exploited for the development of electrochemical biosensors. Also, the processes of adsorption and electro oxidation of glucose on a platinum electrode surface have been investigated. We recorded capacitance measurements of a Platinum working electrode before and after glucose adsorption in buffered solutions. We noticed that the obtained results explain the adsorption phenomenon of glucose on platinum accompanied by capacitance changes. Therefore, with our approach we have been successful in studying the molecular surface interactions and capturing the surface events using our novel double layer capacitance measurements.

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