A third-generation hydrogen peroxide biosensor fabricated with hemoglobin and Triton X-100

A new film of Triton X-100 to incorporate hemoglobin for biosensor fabrication is presented in this paper. In this film, hemoglobin displays a pair of redox peaks in pH 6.0 NaAc-HAc buffer solution with a formal potential of -0.257 V (versus SCE) and shows a thin-layer behavior. Without electron mediator or promoter, the modified electrode has an electrocatalytic activity to the reduction of hydrogen peroxide (H2O2), which shows a linear dependence on the H2O2 concentration ranging from 1.0 x 10(-6) to 1.0 x 10(-4) mol/L. The detection limit of 3.0 x 10(-7) mol/L is estimated when the signal-to-noise ratio is 3. The K-M(app) value of hemoglobin in Triton X-100 film has been determined to be 4.27 mmol/L. Ascorbate, uric acid, dopamine, catechol, cystine and epinephrine will not interfere with the sensitive determination of H2O2. (c) 2004 Elsevier B.V All rights reserved.