Facile fabrication of a superior electrochemical sensor with anti-fouling properties for sensitive and selective determination of glutathione

A novel electrochemical sensor was proposed for sensitive and selective detection of glutathione (GSH). The as -fabricated sensor composed of chitosan (Chit), polyethylene glycol (PEG-OH), porous magnesium metasilicate (PMMS), and silver nanoparticles (AgNPs). Chit and PEG were used as anti-fouling nanomaterials, while PMMS acted as a porous adsorbent that loads large amounts of Cu(II). AgNPs increased the conductivity and the electro-catalytic activity of nanocomposite; besides, it enhanced the adsorption of GSH. Based on the electro-catalytic ability of Cu(II) released from Cu(II)-PMMS, the platform could achieve sensitive and selective determination of GSH without the addition of free Cu(II) in the measured solution. Under optimal conditions, a characteristic peak of GSH-Cu(II) was observed at ca. 0.43 V, which was increased linearly with GSH concentration in the range 0.1 to 125 mu M with a detection limit (LOD, S/N = 3) of 0.03 mu M. The sensor exhibited excellent sensitivity, anti-fouling performance, good selectivity, and sufficient stability. More importantly, the sensor was successfully applied for the estimation of GSH in dietary supplements and human plasma serum samples with acceptable recoveries % (98.3-104.1%) and RSDs values not more than 3.2%. These results proved that the as-fabricated sensor can be used for monitoring of GSH during medical diagnosis.

Automated summary

A novel electrochemical sensor composed of chitosan, polyethylene glycol, porous magnesium metasilicate, and silver nanoparticles was proposed for sensitive and selective detection of glutathione (GSH). The sensor exhibited excellent sensitivity, anti-fouling performance, good selectivity, and sufficient stability. More importantly, it was successfully applied for the estimation of GSH in dietary supplements and human plasma serum samples with acceptable recoveries and RSDs values.