Determination of L-cysteine at Iron Tetrasulfonated Phthalocyanine Decorated Multiwalled Carbon Nanotubes Film Modified Electrode

摘要

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 uniformdecoration of the FeTsPc at the surface of MWCNT. MWCNT-FeTsPc composite modified GCE hasbeen prepared which exhibited prominently enhanced electrocatalytic performance to the oxidation ofL-Cys with two oxidation peaks that are associated with FeTsPc mediated electrocatalysis. Theoverpotential of the oxidation peaks were greatly reduced to 0 .1 V and + 0.22 V, while the peakcurrents were significantly improved in comparison with control electrodes. An amperometric sensorwas fabricated which exhibited excellent electroanalytical parameters for the determination of L-Cysincluding wide linear range (i0 M to 0.2 mM) and very low detection limit (1 M). Practicalfeasibility of the sensor has been assessed in human urine samples. Moreover, the sensor exhibitedexcellent stability, repeatability and reproducibility results.