Electrocatalytic response of dopamine at a thiolactic acid self-assembled gold electrode

The thiolactic acid (TLA) self-assembled monolayer modified gold electrode (TLA/Au) is demonstrated to catalyze the electrochemical response of dopami ne (DA) by cyclic voltammetry. A pair of well-defined redox waves were obta ined and the calculated standard rate constant (ks) is 0.525 cm/s at the se ll-assembled electrode. The electrode reaction is a reversible process. The oxidation peak of DA can be used to determine the concentration of DA. The peak current and the concentration of DA have a linear relationship in the range of 4.0 x 10(-5)-8.0 x 10(-4) mol/l. The detection limit is 3.0 x 10( -6) mol/l. The TLA-SAM was characterized with X-ray photoelectron spectrosc opy (XPS) and a contact angle goniometer. (C) 2001 Elsevier Science B.V. Al l rights reserved.