A highly selective method for the electrochemical detection of reduced glutathione (GSH) has been developed on the basis of the product of a reaction between GSH and catechol as the electron mediator on single-walled carbon nanotubes modified glassy carbon electrode. A polymerization-adduct ECE mechanism at SWNTs/GCE was proposed. The oxidation peak potential was -0.160 V (vs. Ag/AgCl, sat. KCl) and the oxidation peak current showed a dependence relationship with GSH concentration in the range of 1.0 similar to 500.0 mu M with a detection limit of 0.5 mu M GSH. The developed method can discriminate GSH from other thiol species such as L-cysteine (Cys) and cysteamine hydrochloride (Cym) within their certain concentration ranges. The as-established electrochemical method has been successfully applied for the determination of GSH from the leakage of intracellular GSH contents in HeLa cells following doxorubicin-induced cell apoptosis. (C) 2016 Elsevier Ltd. All rights reserved.