Adsorption-desorption study of BSA conjugated silver nanoparticles (Ag/BSA NPs) on collagen immobilized substrates

There has been a growing interest in the use of protein conjugated nanoparticles for applications in biomedical, sensing, and advanced imaging. The objective of this study was to understand the interaction of protein conjugated silver nanoparticles (Ag/BSA NPs) with biological substrate (collagen layer). The adsorption behavior of synthesized Ag/BSA NPs on collagen immobilized silanized surface was followed by UV-vis spectroscopy by initially studying the formation of collagen layer and subsequent adsorption of Ag/BSA NPs to the immobilized layer. Surface plasmon resonance (SPR) data provided the real time profile of adsorption of Ag/BSA NPs from solution onto collagen immobilized and control substrates as well as desorption of nanoparticles from the substrates. The retention of NPs to substrate is sensitive to chemistry of the underlying substrate and on the external environment. UV-vis and atomic absorption spectrometric analysis of Ag/BSA NPs desorption performed under different pH conditions showed more NPs retained at physiological pH than the acidic and basic conditions. Nanoparticles retention on collagen immobilized substrate at physiological pH could influence properties of biological interest such as circulation lifetime and biodistribution of nanoparticles in the body.