Electrochimica Acta, Vol.88, 24-34, 2013
Electrochemically imprinted molecular recognition sites on multiwalled carbon-nanotubes/pencil graphite electrode surface for enantioselective detection of D- and L-aspartic acid
Molecularly imprinted polymeric nano-materials (thickness 2.03 nm) for aspartic acid enantiomers were electrochemically synthesized onto multi-walled carbon nanotubes immobilized pencil graphite electrode surface. The molecular recognition in this work was based on doping/de-doping characteristics of the conducting polymer, poly (indole-3-acetic acid), wherein the template (aspartic acid) acted as a dopant which could easily be ejected from the polymer backbone after over-oxidation. This resulted in molecular cavities complementary to the template in the imprinted polymer texture. The transduction was made via differential pulse anodic stripping voltammetric detection of D- and L-aspartic acid using respective sensors. The detection limits (S/N = 3) for D- and L-aspartic acid were found to be 0.025 and 0.016 mu M, respectively in aqueous solutions. Enantioselective analysis of L-aspartic acid was validated in real samples that suggested practicability of the proposed sensor for the evaluation of this bioactive molecule as a disease biomarker in clinical settings, without any cross-reactivity and false-positives. (C) 2012 Elsevier Ltd. All rights reserved.
Keywords:Doping/de-doping;Molecularly imprinted polymer;D- and L-Aspartic acid;Electropolymerization;Poly (indole-3-acetic acid)