In Situ Synthesis of a Novel Quinone Imine Self-Assembled Monolayer and Consideration of Its Reactivity with L-Arginine
In situ functionalization of a 4-aminothiophenol (4ATP) self-assembled monolayer (SAM) on a Au electrode (4ATP/Au SAM) by the Michael addition reaction is considered. Under optimized conditions, the nucleophilic attack of the amino group of 4ATP/Au SAM to give an electrogenerated ortho-quinone produced a novel electroactive SAM (ESAM). The ESAM could be oxidized to quinone-imine SAM (QI SAM) for the covalent immobilization of L-arginine monolayers. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and Fourier transform infrared (FTIR) spectroscopy are employed to characterize these systems.. The apparent heterogeneous rate constant (ksapp) for ESAM/Au and the rate constant (k') of the pseudo-first order Michael addition reaction of L-arginine and ESAM/Au are calculated.