Formation of Poly-l-lysine Monolayers on Silica: Modeling and Experimental Studies

Modification of solid substrates by poly-L-lysine (PLL) layers has been widely employed in order to improve their biocompatibility, for promoting protein and cell immobilization for fabrication of biosensor arrays and antibacterial coatings. However, despite many studies conducted in the literature there is deficiency in a quantitative description of PLL adsorption processes. It is postulated that this becomes feasible applying direct experimental techniques combined with through theoretical modeling. In this work the kinetic of PLL adsorption on silica for various ionic strengths was determined in situ under controlled flow conditions using the optical reflectometry and the streaming potential methods. Both, the initial adsorption rates and longer time kinetic runs, were acquired and quantitatively interpreted in terms of the convective-diffusion and the random sequential adsorption theoretical modeling based on the coarse grained Monte-Carlo approach. This unique combination of experimental and theoreti...