In vivo monitoring of the thiols in rat striatum by liquid chromatography with amperometric detection at a functionalized multi-wall carbon nanotubes modified electrode

A new chemically modified electrode (CME) was fabricated, which was based on the immobilization of multi-wall carbon nanotubes fuctionalized with carboxylic group (MWNT-COOH). The results indicated that the CME exhibited efficiently electrocatalytic oxidation for L-cysteine and glutathione with relatively high sensitivity, stability and long-life. Coupled with HPLC, the MWNT-COOH CME was utilized for amperometric detection of the thiols. The peak currents of L-cysteine and glutathione were linear to their concentrations ranging from 3.0 × 10^-7 to 1.0 × 10^-3 mol/L with the calculated detection limit (S/N = 3) of 1.2 × 10^-7, 2.2 × 10^-7 mol/L, respectively. The method had been successfully applied to assess the contents of L-cysteine and glutathione in rat striatal microdialysates.