AFM and SPR studies of protein adsorption at solid/liquid interface

Authors

Rafael Arechabaleta, Florida International University

Document Type

Thesis

Degree

Master of Science (MS)

Major/Program

Physics

First Advisor's Name

Nongjian Tao

First Advisor's Committee Title

Committee Chair

Second Advisor's Name

Yesim Darici

Third Advisor's Name

John T. Landrum

Fourth Advisor's Name

Yifu Zhu

Date of Defense

7-9-1999

Abstract

Membrane-like structure formed by surfactant molecules of didodecyldimethylammonium bromide (DDAB) on both HOPG and gold electrodes were studied with AFM and SPR techniques. The study shows that the thickness of the adsorbed layer of DDAB is strongly dependent on the concentration of the vesicle solution.

We have also investigated the adsorption of redox protein, Cytochrome c, on graphite electrode with in situ tapping mode AFM. The protein adsorbs spontaneously onto the electrode covered with an adsorbed phosphate layer and forms a uniform monolayer. The adsorbed protein exhibits a reversible electron transfer at 0.17 V (Ag/AgCI) once the electrode potential has been increased to 0.75V.

Using surface plasmon resonance spectroscopy we have measured subtle conformational change in protein, Cyt c, due to electron transfer of a single electron on MPA-coated gold electrode. The electron transfer induced change in the resonant angle is about 0.006 deg., which corresponds to ~ 0.2 A decreases in the thickness. This is consistent with that reduced state is more compact than the oxidized state.

Identifier

FI14030206

Recommended Citation

Arechabaleta, Rafael, "AFM and SPR studies of protein adsorption at solid/liquid interface" (1999). FIU Electronic Theses and Dissertations. 1054.
https://digitalcommons.fiu.edu/etd/1054