Abstract
A sensitive amperometric sensing platform has been developed for the determination of L-Cysteine (L-Cys) at iron tetrasulfonated phthalocyanine (FeTsPc) decorated multiwalled carbon nanotubes (MWCNT) composite film modified electrode. Surface morphological studies revealed uniform decoration of the FeTsPc at the surface of MWCNT. MWCNT-FeTsPc composite modified GCE has been prepared which exhibited prominently enhanced electrocatalytic performance to the oxidation of L-Cys with two oxidation peaks that are associated with FeTsPc mediated electrocatalysis. The overpotential of the oxidation peaks were greatly reduced to - 0.1 V and + 0.22 V, while the peak currents were significantly improved in comparison with control electrodes. An amperometric sensor was fabricated which exhibited excellent electroanalytical parameters for the determination of L-Cys including wide linear range (i0 mu M to 0.2 mM) and very low detection limit (1 mu M). Practical feasibility of the sensor has been assessed in human urine samples. Moreover, the sensor exhibited excellent stability, repeatability and reproducibility results.