A novel gold nanoparticle decorated nanocrystalline zeolite based electrochemical sensor for the nanomolar simultaneous detection of cysteine and glutathione

In this work, highly dispersed gold nanoparticle decorated nanocrystalline zeolite was synthesized by the electrostatic interaction between the functionalized gold nanoparticles and functionalized nanocrystalline zeolite. An electrochemical sensor based on the gold nanoparticle decorated nanocrystalline zeolite was developed for the nanomolar simultaneous detection of cysteine and glutathione with high sensitivity, selectivity, and remarkably low detection limit. A wide linear range was obtained from 2 nM to 800 mu M and 3 nM to 800 mu M with a limit of detection of 0.3 nM and 0.6 nM for cysteine and glutathione, respectively. The analytical performance of the developed sensor was demonstrated in the determination of cysteine and glutathione in commercial pharmaceutical preparations with satisfactory results even in the presence of several amino acids. The proposed methodology provides promising application in clinical diagnostic and drug analysis.