Electrochemical impedance based chiral analysis of anti-ascorbutic drug: L-ascorbic acid and D-ascorbic acid using C-dots decorated conductive polymer nano-composite electrode

Abstract

Clinical manifestations owing to L-ascorbic acid for scurvy as comparison to D-ascorbic acid and challenges of chiral purity are overcome by using chiral selective conductive polymer nanocomposite which mimics antibodies and enzymes. A novel chiral selective imprinted polyaniline–ferrocene–sulfonic acid film has been electrochemically fabricated on C-dots modified pencil graphite electrode. The performance of the obtained L-ascorbic acid or D-ascorbic acid chiral selective sensor was investigated by electrochemical impedance spectroscopy, cyclic and differential pulse voltammetry. The surface characteristics of the C-dots, chiral sensor before and after the de-doping of chiral D- and L-ascorbic acid were characterized by scanning electron microscopy, Raman spectroscopy and X-ray diffraction spectroscopy. Excellent recognition results were obtained by difference in electron transfer resistance. The proposed chiral sensor is capable of measuring D-ascorbic acid or L-ascorbic acid in aqueous as well as in real and commercial samples within the range of 0.020–0.187 nM and 0.003–0.232 nM with detection limit of 0.00073 nM and 0.00016 nM, respectively. The proposed method has also been examined for the chiral selective recognition of ascorbic acid isomers (D- and L-) quantitatively, in complicated matrices of real samples.