A High sensitivity impedimetric biosensor using the tannin from quercusmacrolepis as biorecognition element for heavy metals detection
Résumé
A new poly(vinylchloride) (PVC) membrane electrode based on tannin from the bark of Quercusmacrolepis (acorn) as the ionophore was prepared and modified onto the surface of a gold electrode. The electrochemical impedance spectroscopy (EIS) technique was used to study the sensitivity of the electrode that was modified with a thin layer of polymeric biomembrane, in order to detect heavy metals ions in solution. The device shows a good sensitivity for Zn2+, Ni2+ ions and a little less for Cd2+. The electrode indicates a good linear response for the three metals over a wide concentration range from 1.0 x 10(-19) to 1.0 x 10(-4) M, with a detection limit of 1.0 x 10(-9) M.