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

Abstract

The thiolactic acid (TLA) self-assembled monolayer modified gold electrode (TLA/Au) is demonstrated to catalyze the electrochemical response of norepinephrine (NE) by cyclic voltammetry. A pair of well-defined redox waves were obtained and the calculated standard rate constant ( k s) is 5.11×10 −3 cm s −1 at the self-assembled electrode. The electrode reaction is a pseudo-reversible process. The peak current and the concentration of NE are a linear relationship in the range of 4.0×10 −5–2.0×10 −3 mol l −1. The detection limit is 2.0×10 −6 mol l −1. By ac impedance spectroscopy the apparent electron transfer rate constant ( k app) of Fe(CN) 3−/Fe(CN) 4− at the TLA/Au electrode was obtained as 2.5×10 −5 cm s −1.