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Abstract
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A sol–gel derived renewable biosensor was prepared
by entrapping hemoglobin (Hb) in a mesoporous carbon ceramic
electrode (MCCE) in order to study the direct electron transfer of
Hb and to fabricate a sensitive biosensor for hydrogen peroxide
(H2O2). The Hb in the MCCE retained its original structure and
still displayed good electrochemical activity in showing a pair of
well-defined redox peaks as a result of direct electron transfer
between Hb and the electrode surface. The MCCE possesses
good biocompatibility, renewability, uniformity, and is well suited
for immobilization of enzymes. The immobilized Hb was
found to display good electrocatalytic activity for the reduction
of H2O2, and this resulted in the design of an amperometric
biosensor working at −0.3 Vand capable of sensing H2O2 with a
detection limit of 0.4 μM(at a S/N of 3). The catalytic reduction
current is proportional to the concentration of H2O2 in the 1.0 to
220.0 μM range. This work demonstrates MCCE to be a well
suited and easily accessible substrate for engineering biosensors
with various kinds of potential applications.
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