Study of the adsorption of fibrinogen on gold-coated silicon wafer by an impedance method.
In 0.1 mol/l KH(2)PO(4)-Na(2)HPO(4) (pH 7.80) buffer solution, the potential of zero charge (PZC) and the open circuit potential of gold-coated silicon were determined to be about -0.6 and +0.10 V (vs SCE), respectively. The open circuit potential was higher than the PZC, which indicated that the surface of the gold-coated electrode had a positive charge. The ellipsometry experiment showed that the adsorption of fibrinogen onto the gold-coated silicon wafer surface arrived at a saturated state when the adsorption time exceeded 50 min. The percentage of surface without adsorbed protein, theta, was about 63%. This means that the proportion of surface actually occupied by fibrinogen was only about 37% after the adsorption arrived at saturation. The solution/protein capacitance value was determined in an impulse state around -0.59 V (vs SCE) and was stable (4.2x10(-5) F) at other potentials.
Yu
Yong
Y
Laboratory of National Microgravity, Institute of Mechanics, Chinese Academy of Science, 100080, Beijing, People's Republic of China.
Jin
Gang
G
D000327:Adsorption; D004563:Electrochemistry / Q000379:methods*; D004566:Electrodes; D005340:Fibrinogen / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D012825:Silicon / Q000737:chemistry*; D013997:Time Factors
D006046:Gold; D005340:Fibrinogen; D012825:Silicon