Enzymatic formation of ions and their detection at a three-phase electrode
An electrochemical method for the detection of enzymatically created anions is described that uses a thin-film electrode with decamethylferrocene as an electroactive redox probe. The enzymatic oxidation of glucose with enzyme glucose oxidase produces gluconic acid as a final product. The oxidation of decamethylferrocene dissolved in the thin-nitrobenzene film, that is spread on the working graphite electrode and submerged in the aqueous solution containing glucose and glucose oxidase, is followed by the up-take of gluconate anions from the aqueous phase to nitrobenzene. The peak currents of the square-wave voltammetric responses of that system are a linear function of the glucose concentration in the milimolar range from 0.1 mmol/L to 0.7 mmol/L (R2=0.994).
KeywordsGlucose Enzymatic reactions Biosensor Thin-film electrode Ion transfer Decamethylferrocene
Rubin Gulaboski thanks Fundação para a Ciência e a Tecnologia (FCT) of Portugal for providing of a post. doc. fellowship (SFRH/BPD/14894/2004). The authors would like to thank FCT for financial support (CIQ L4 and FEDER for the project POCTI/QUI/42472/2001).
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