Acid stability of carbon paste enzyme electrodes

作者：Wang Joseph^*; Musameh Mustafa; Mo Jian Wei

来源：Analytical Chemistry, 2006, 78(19): 7044-7047.

DOI：10.1021/ac060986g

This note reports on the unusual protection of several enzymes against harsh pH conditions provided by carbon paste electrodes. Both glucose oxidase and polyphenol oxidase carbon paste amperometric biosensors display a remarkable resistance to acid deactivation compared to conventional biosensors prepared by electropolymeric entrapment of enzymes. For example, the carbon paste enzyme electrodes fully retain their activity upon stressing in strongly acidic conditions ( pH similar to 2.0-2.5) for prolonged periods, where conventional (polymer-based) biosensors rapidly lose most of their response. Such unusual acid stability of carbon paste enzyme electrodes is attributed to the "pH memory" of enzymes in the hydrophobic paste environment, to the barrier to hydronium ions provided by the pasting liquid and to decreased conformational mobility.

• 出版日期2006-10-1