Electrocatalytic response of norepinephrine 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 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.