Catalytic oxidation of ascorbic acid on 2D and 3D monolayers of 4-hydroxythiophenol

Monolayers of 4-hydroxythiophenol (4-HTP) immobilized on gold electrode (213 SAMs) or gold nanoclusters (31) SAMs) lead to catalytic oxidation of ascorbic acid (AA). The catalytic role of the modified clusters was revealed by comparing the electrodes covered by 1,9-nonanedithiol and the same nonanedithiol monolayer decorated by 4-HTP protected clusters. The 4-HTP protected gold nanoclusters supported on a metal surface using a monolayer of 1,9-nonanedithiol as the bridge, transferred charge to ascorbic acid (AA) molecule in the solution more efficiently than when the same 4-HTP monolayer was formed directly on the gold electrode.