No abstract

Using 3-Aminopropyltriethoxysilane(APTES) as a single silica source, an amino-rich ultrafine organosilica-nanoparticle-modified Au electrode was fabricated, following the formation of (3-mercaptopropyl)-trimethoxysilane (MPTS) monolayer on Au surface (MPTS/Au). With cetyltrimethylammonium bromide as an additive, APTESbased gel particles on the electrode have a narrow particle size distribution of 4-7 nm and "crystal-like" structure. AFM and electrochemical characterization confirmed the successful grafting of APTES nanoparticles on MPTS/Au. The APTES/MPTS/Au electrode is highly sensitive for the detection of copper(II) ions with a detection limit as low as 1.6 10 À12 mol L À1 (S/N > 3) by square wave voltammetry. The current is linear to copper(II) concentration between 1.6 10 À12 and 6.25 10 À10 mol L À1.