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 (ks) 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 (kapp) of Fe(CN)3−/Fe(CN)4− at the TLA/Au electrode was obtained as 2.5×10−5 cm s−1.