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

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. (C) 2015 Elsevier B.V. All rights reserved.