Chiral recognition of penicillamine enantiomers based on a vancomycin membrane electrode

Abstract

An enantioselective membrane electrode based on vancomycin (Van) was proposed for the assay of penicillamine enantiomers. Cyclic voltammetry, electrochemical impedance spectroscopy, atomic force microscopy and UV-Vis spectra were employed to investigate the chiral recognition phenomenon. The results exhibited that the binding effect between D-penicillamine (D-Pen) and the proposed Van membrane electrode was obviously stronger than that of L-penicillamine (L-Pen). In addition, the amount of Van, the pH of the supporting electrolyte solution and the concentration of Pen enantiomers were systematically investigated and optimized. The association constant (K) was calculated to be 1.05 × 10⁴ L mol⁻¹ for D-Pen and 1.40 × 10² L mol⁻¹ for L-Pen. The enantioselective concentration range of the proposed membrane electrode is 10⁻⁷ to 10⁻² mol L⁻¹. The results suggested that the chiral selective membrane has the potential to discriminate and determine chiral drugs in the pharmaceutical application of electrochemical analysis.