Control of selective adsorption behavior of Ti-binding ferritin on a SiO_2 substrate by atomic-scale modulation of local surface charges

摘要

We have systematically investigated the influence of local surface potential distribution on selective adsorption of Ti-binding ferritin (TBF) on SiO_2 substrates. We found that the TBF exhibits the adsorption ability onto Ti-decorated SiO_2 surface of less than one atomic layer coverage. This experimental finding enabled us to propose a model in which the positively charged sites and their nanometer-scale interval are the dominant factors that determine bond strength between TBF and SiO_2 surfaces. Furthermore, on the basis of this model, the adsorption behavior of TBF onto bare SiO_2 surfaces was controlled by generation and/or recovery of electrical defects in SiO_2.