Low-cost electrochemical detection of l-tyrosine using an rGO–Cu modified pencil graphite electrode and its surface orientation on a Ag electrode using an ex situ spectroelectrochemical method

Abstract

A low cost reduced graphene oxide–copper hybrid nano thin-film modified Pencil Graphite Electrode has been employed to detect the L-tyrosine enantiomer. The free-standing rGO–Cu hybrid nano-thin film was prepared by a simple one-step liquid–liquid interface method. Electrochemical Cyclic Voltammetry, Differential Pulse Voltammetry, pH-dependent and scan rate dependent studies on bare PGE, Cu, rGO, and rGO–Cu for L-tyrosine have been explained in detail. The rGO–Cu modified PGE based biosensor exhibits good detection of L-tyrosine. The linear range detection limit was estimated to be 1 × 10⁻⁷ M. The calculated sensitivity is 0.4 μA ppm⁻¹ mm². This electroactive biosensor is easily fabricated and controlled and is cost-effective. The surface orientation of L-tyrosine on the Ag electrode at a particular potential and its comparison with vibrational DFT calculations have been studied for the first time.