Gold nanoparticles adsorption study onto periodic block copolymer using quartz crystal microbalance

In this work, we have studied adsorption and aggregation characteristics of citrate stabilized gold nanoparticles (AuNPs) onto periodic block copolymer using a quartz crystal microbalance (QCM) technique. Thin film of polystyrene block-poly (2-vinylpyridine) (PS-b-P2VP) template was coated onto gold Q-sense sensor crystals to study the adsorption and aggregation characteristics of AuNPs. The template pattern was controlled through an oxygen plasma reactive ion etching (RIE) process. Height of the template was varied from 50 nm to 20 nm with the inter-particle separation of similar to 200 nm. Adsorption studies of AuNPs were carried out in-situ and in real time by means of the QCM technique. There is change in frequency of the Q-sense sensor crystal with the variation in mass/volume of pattern polymer template. The adsorption and aggregation characteristics of AuNPs onto a pattern template substrate were studied using AFM and QCM analysis. The arrays of gold nanoparticle clusters presenting a systematic variation in number of AuNPs due to different template dimensions show a mean intra-particle separation below 10 nm. (C) 2015 Elsevier B.V. All rights reserved.