A molecule with dual functionality 4-aminophenylmethylphosphonic acid: A comparison between layers formed on indium tin oxide by in situ generation of an aryl diazonium salt or by self-assembly of the phosphonic acid

摘要

4-Aminophenylmethylphosphonic acid was grafted on ITO surfaces by 1) electrochemical reductive adsorption of the corresponding aryl diazonium salt and 2) by self-assembly via the phosphonic acid moiety. The aryl diazonium salt derived surfaces are reasonably stable within a wide potential range from -600mV to 600mV compared to a very narrow stable range between -40mV and 40mV for the self-assembled layers. The different surface stabilities were assessed with a view to forming ITO-organic layer-gold nanoparticle (AuNPs) constructs. As expected the ITO-organic layer-AuNPs construct formed by electrochemical adsorption (ITO-Ph-AuNP) was significantly more stable than the construct formed by self-assembly of phosphonates (ITO-PO_3Ph-AuNPs).