Recognition of glutathione based on its electrocatalytic oxidation on the bare fluorine doped tin oxide electrode

- Bare fluorine doped tin oxide (FTO) can catalyze glutathione (GSH) oxidation.
- Electrocatalytic oxidation of GSH at FTO electrode is very sensitive to pH.
- Lower oxidation peak potential of GSH at the FTO electrode
- A novel strategy for recognition of GSH from the 20 α-amino acids and other species
- Detection limit for recognition of GSH is 5 nM at pH 4.4.

We revealed that the bare fluorine doped tin oxide (FTO) exhibited the electrocatalytic ability towards the oxidation of glutathione (GSH) in a narrow pH region, which was examined using linear sweep voltammetry (LSV). LSV indicated that an oxidation peak of GSH at the FTO electrode occurs at 0.27 V (vs. SCE) that is 0.77 V negative of that at the bare Pt electrode, and GSH cannot be oxidized at the glassy carbon (GC) electrode in a potential region − 0.40 to 1.20 V, at pH 4.4. On the basis of the electrocatalytic oxidation of GSH in a narrow pH region 4.0-5.5 and its lower oxidation peak potential, the bare FTO electrode can be used as a probe to recognize GSH from the 20 α-amino acids present in proteins, cystine, homocysteine, cysteamine, thiobenzoic acid, ascorbic acid, catechol, and dopamine. Its detection limit for the recognition of GSH is 5 nM.

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