A new nano biosensore for determination of L-cysteine on gold nanoparticles- modified carbon ceramic electrode

Carbon ceramic electrodes were prepared by sol–gel processing of a hydrophobic precursor methyltrimethoxysilane (MTMOS) together with dispersed graphite microparticles according to a literature procedure. The electrochemical behavior of L-cysteine at the surface of a carbon ceramic electrode (CCE) modified with gold nanoparticles (GNPs) is described. The modified electrode showed excellent catalytic activity toward L-cysteine reduction and can be used successfully for amperometric detection of L-cysteine. Under the optimized conditions, the calibration plots are linear in the concentration range 0.165 mM- 2.64 mM. Detection limit (signal to noise is 3) and sensitivity were found to be 0.053 mM and 1769 nA / mM, respectively.