Enantiomeric electro-oxidation of D- and L-glucose on chiral gold single crystal surfaces

The enantioselectivity of the gold chiral surfaces towards the electrocatalvtic oxidation of D- and L-glucose in neutral phosphate-buffered media is reported. Two enantiomorphic surfaces were used, Au{32}(R) and Au{321}(S), and results obtained by cyclic voltammetry were compared with two non-chiral surfaces having the same terrace and step orientations, Au(111) and Au(211). All enantioselective effect is observed, Au {321}(R) exhibits a higher activity for D-glucose while Au{3 2 1}(S) exhibits a higher activity for L-glucose. The corresponding en anti oselectivity factor was estimated to 10% for the process occurring at lower potential values and to 50% for the process at higher potential values. These results represent the first evidence that gold chiral surfaces are capable of enantiomeric discrimination. (C) 2003 Elsevier B.V. All rights reserved.