Electrochemical Sensors based on Conducting Polymer Modified Electrodes and Microelectrodes for Electroanalysis of Ascorbic Acid

摘要

Conventional-size electrodes and microelectrodes coated by electrogenerated poly[4,4′-bis(butylsulfanyl)-2,2′-bithiophene] have been tested with respect to the electrocatalytic oxidation of a particularly meaningful analyte, viz., ascorbic acid, in phosphate buffered aqueous solution. Linear sweep (cyclic) vcltammetry has been used and the quantities related to the analyte concentration were the peak current and the diffusion (t~(-1/2))-deconvoluted peak current in the case of conventional-size and of microelectrode, respectively. Fairly good linear correlation could be found, the linearity range resulting from 1 x 10~(-3) M to 1.5 x 10~(-2) M for the conventional-size electrode and from 1 x 10~(-6) M to 1 x 10~(-3) M for the microelectrode, respectively. The microelectrode showed to work quite well also at a very low (10~(-4) M) phosphate buffer-supporting electrolyte concentration.