Simultaneous determination of ascorbic acid, dopamine, uric acid and hydrogen peroxide based on co-immobilization of PEDOT and FAD using multi-walled carbon nanotubes

摘要

A simple method was used to synthesize active hybrid composites containing multi-walled carbon nanotubes (MWCNTs), poly(3,4-ethylenedioxythiophene) (PEDOT) and flavin adenine dinucleotide (FAD). The MWCNT/PEDOTa€“FAD hybrid composite had good electrocatalytic properties for ascorbic acid, dopamine, uric acid and hydrogen peroxide compared with PEDOT, PEDOTa€“FAD, MWCNT/PEDOT and PEDOTa€“FAD/MWCNT. It had a linear concentration range of 4 ?— 10a?’4 to 8 ?— 10a?’3 M for ascorbic acid, 6 ?— 10a?’6 to 7.5 ?— 10a?’5 M for dopamine and 2 ?— 10a?’6 to 4 ?— 10a?’5 M for uric acid. The sensitivities were 36 ??A mMa?’1 cma?’2 for ascorbic acid, 5154 ??A mMa?’1 cma?’2 for dopamine and 14286 ??A mMa?’1 cma?’2 for uric acid. The detection limits were 4 ?— 10a?’4 M for ascorbic acid, 6 ?— 10a?’6 M for dopamine and 2 ?— 10a?’6 M for uric acid (S/N = 3). It also showed good electrocatalytic reduction of H2O2 with a linear concentration range of 5 ?— 10a?’4 to 9 ?— 10a?’3 M, a sensitivity of 52 ??A mMa?’1 cma?’2 and a detection limit of 5 ?— 10a?’4 M (S/N = 3). We report here a simple method of synthesizing the active species on the surface of the electrodes for the simultaneous determination of ascorbic acid, dopamine, uric acid and H2O2. This hybrid could be used to develop multifunctional biosensors.