Deposition mechanism of gold nanoparticles on poly(allylamine chloride) modified gold sensor was investigated by the quartz crystal microbalance (QCM) and the scanning electron microscopy (SEM). The influence of the suspension concentration, flow intensity, ionic strength, and pH was systematically studied. It was shown that the deposition kinetics for lower coverage range was characterized by a linear increase of the coverage with the time. A general kinetic equation was: formulated for calculating the particle deposition rates pertinent to the linear regime. Extensive measurements were also carried out for longer times at different ionic strengths and pHs. Negligible desorption of particles was observed that enabled one to precisely determine the maximum coverage of monolayers. These results were quantitatively interpreted in terms of the generalized random sequential adsorption (eRSA) model that considers the bulk and surface transfer steps in a rigorous way, It was proven, by comparing the QCM data with the SEM results, that the monolayer hydration was negligible. The structure:of monolayers obtained for various ionic strengths was also analyzed in terms of the radial distribution function by using the SEM micrographs of deposited particles.
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