Figure 2: SW voltammograms (δ current) of increasing concentrations of GSH dissolved in 0.1 mmol/L phosphate buffer (pH 7.5). a=12.5; b=37.5; c=62.5; d=125; e=187.5 μmol/L. Each voltammogram represents the mean of five independent experiments. Other experimental conditions were the same as those described in figure. 1.