title: Tunable surface-enhanced infrared absorption on au nanofilms on si fabricated by self-assembly and growth of colloidal particles.
abstract: Au colloids were used to fabricate nanoscale-tunable Au nanofilms on silicon for surface-enhanced IR absorption bases in both ambient and electrochemical environments. This wet process incorporates the self-assembly of colloidal Au monolayer using 3-aminopropyl trimethoxysilane as the organic coupler with subsequent chemical plating in an Au(III)/hydroxylamine solution. FTIR spectroscopy in transmission mode of the probe species SCN- was used to evaluate the apparent surface enhancement in IR absorption of 2D Au colloid arrays and chemically plated Au particles. The nanostructure of Au films was examined by atomic force microscopy. The IR and AFM results show that the apparent surface enhancement factor (1-2 orders of magnitude) increases with increasing sizes and/or contact, and the severe aggregation of Au nanoparticles may cause the bipolar band shape. Cyclic voltammetry on the Au nanofilm obtained by the above nucleation and growth strategy exhibits a feasible electrochemical stability and behavior. In situ ATR-FTIR measurement of p-nitrobenzoic acid adsorption demonstrates that the as-grown Au film yields rather promising surface enhancement as well.
authors.affiliation: Shanghai Key Laboratory for Molecular Catalysis and Innovative Materials and Department of Chemistry, Fudan University, Shanghai 200433, China.
authors.forename: Sheng-Juan
authors.initials: SJ
authors.lastname: Huo
authors.forename: Qiao-Xia
authors.initials: QX
authors.lastname: Li
authors.forename: Yan-Gang
authors.initials: YG
authors.lastname: Yan
authors.forename: Yi
authors.initials: Y
authors.lastname: Chen
authors.forename: Wen-Bin
authors.initials: WB
authors.lastname: Cai
authors.forename: Qun-Jie
authors.initials: QJ
authors.lastname: Xu
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Osawa