| 초록 |
Proteins in biological systems have a general tendency to adsorb at surfaces, yet a detailed understanding of the interaction between surfaces and proteins and kinetics are poorly understood. Ellipsometry, as one of non-invasive surface sensitive techniques, can be used to study the adsorption kinetics, where the several sub-process occur sequentially during the adsorption. In this study, our aim is to understand how the protein behaves differently, as we vary the surface characteristics, in particular, with different charge density. Variously charged surfaces were obtained by a spin-casting of poly(styrene-ran-styrene sulfuric acid) (PSSA) and poly(styrene-ran-acrylic acid) (PSAA) with a series of charge contents, from 0 to 15 %. The system was modeled with five independent layers, including silicon (substrate), native oxide, polymer thin film, proteins and a buffer medium. From that model, we could determine the exact values of the thickness and amount of adsorbed proteins on various charged surfaces, further surface kinetics, strongly influenced by the surface charge densities. |
