An electrochemical glutathione biosensor: Ubiquinone as a transducer

In this paper, coenzyme Q 10 (Ubiquinone, CoQ 10 ) was used for the first time as a transducer to construct electrochemical biosensor for effectively detecting γ- l -glutamyl- l -cysteinyl-glycine (glutathione, GSH). CoQ 10 modified electrode was fabricated by attaching its gel mixed with multi-walled carbon nanotubes (MWNTs)/ionic liquid (IL). In the optimum conditions, based on the increasing of reduction peak current of CoQ 10 caused by GSH through voltammetric technology, it was found that the peak current of CoQ 10 was linear with the concentration of GSH in the range from 4.0×10 −9 to 2.0×10 −7   mol   L −1 at the pH 7.00, and the limit of detection was 3.2×10 −10   mol   L −1 ( S / N =3). The results revealed that this method could be used to determine GSH in actual blood samples with the superiority of excellent selectivity , high stability and sensitivity. The strategy explored here might provide a new pathway to design novel multi-function transducers for detecting GSH, which has unique characteristic and potential application in the fields of sensor and medical diagnosis.