Surface patterning using scanning electrochemical microscopy to locally trigger a click chemistry reaction

We report on the surface micropatterning of conductive surfaces via the electrochemical triggering of a click reaction, the copper(I) catalyzed azide-alkyne cycloaddition reaction (CuAAC) by SECM via a two-step approach: (i) functionalization on the entire surface with azido-aryl groups by using the diazonium approach followed by (ii) the covalent linkage of alkyne-bearing ferrocene by CuAAC within a local area by SECM. More precisely, the click reaction was triggered by Cu(l) catalyst generation for 30 min at the SECM tip positioned approximate to 10 mu m above the azido-aryl modified surface. The dimension of the spot obtained under these conditions was approximate to 75 mu m. The electrochemical imaging by SECM of the ultra thin area locally clicked with ferrocene moieties was made thanks to the electrocatalytic properties of the ferrocene modified surface towards ferrocyanide electrooxidation. This local clicking procedure opens the gate to further controlled functionalization of restricted small substrates. (C) 2013 Elsevier B.V. All rights reserved.