Gold nanoparticle/alkanedithiol conductive films self-assembled onto gold electrode: Electrochemistry and electroanalytical application for voltammetric determination of trace amount of catechol

This paper describes novel electrochemical properties of gold nanoparticles/alkanedithiol conductive films and their electroanalytical applications for voltammetric determination of trace amount of one kind of environmental pollutants, catechol. The conductive films are prepared by closely packing 12-nm diameter gold nanoparticles (Au-NPs) onto An electrodes modified with the self-assembled monolayers (SAMs) of alkanedithiols (i.e., HS(CH2)(n)SH, n = 3, 6, 9). The assembly of the Au-NPs onto the SAM-modified electrodes essentially restores the heterogeneous electron transfer between An substrate and redox species in solution phase that is almost totally blocked by the SAMs and, as a result, the prepared Au-NP/SAM-modified electrodes possess a good electrode reactivity without a remarkable barrier toward the heterogeneous electron transfer. Moreover, the prepared Au-NP/SAM-modified electrodes are found to exhibit a largely reduced interfacial capacitance, compared with bare An electrode. These electrochemical properties of the Au-NP/SAM-modified electrodes essentially make them very useful for electroanalytical applications, which is illustrated by voltammetric determination of trace amount detection of environmental pollutant, catechol. (c) 2006 Elsevier B.V. All rights reserved.