Stripping chronopotentiometric analysis of cysteine on nano-silver coat polyquercetin–MWCNT modified platinum electrode

摘要

Silver nanoparticles coat polyquercetin (Qu) and multi-walled carbon nanotube (MWCNT) complex films were prepared using an electrochemical coupling strategy on platinum electrode (Ag/Qu/MWCNT/Ch/Pt). The new composite material was characterized by means of field emission scanning electron microscopy, X-ray photoelectron spectroscopy spectra, X-ray diffraction, and electrochemical techniques, which confirmed that polyquercetin plays an important role to obtain a great deal of uniformly dispersed silver nanoparticles and MWCNT complex film with a diameter of 10±6 nm. The resulting Ag/Qu/ MWCNT/Ch/Pt electrode shows a significant electrocatalysis for the redox of cysteine (CysH). The stripping chronopotentiometric analysis of CysH has been successfully used with a satisfying effect. A linear range of 1× 1010 to 9×108 M was obtained with a detection limit of 3×1011 M (3) and sensitivity of 35 μAM. The films were also robust, surviving up to 100 consecutive cyclic voltammograms and sonication.