Abstract
Direct electrochemistry of the myoglobin‐triacetone triperoxide (Mb‐TATP) composite on carbon paste (CP) electrode is reported. This electrode gives a well‐defined and quasi‐reversible cyclic voltammogram for the Mb FeIII/FeII redox coupled with the formal potential (E˚′) of −0.302 V (vs. Ag/AgCl) in pH 6.92 phosphate buffer. Electronic and vibrational spectroscopies show that the Mb in the composite retains a structure similar to its native form. The enzymatic reactivity to the reduction of H2O2 has been studied for the Mb‐TATP film. The analytical performances have been obtained with the linear range of 78.32–1135.64 µM, the detection limit of 55 µM (S/N=3), and the apparent Michaelis‐Menten constant (K m) of 662.8 µM. This H2O2 biosensor based on the electrocatalysis of the immobilized Mb presents a higher stability within two weeks.
The authors are gratefully acknowledged for the Natural Science Foundation of Shandong Province (grant No. Y2005B04).