Direct electrochemistry of hemoglobin in dimethyldioctadecyl ammonium bromide film and its electrocatalysis to nitric oxide.

摘要

Hemoglobin (Hb) was successfully immobilized in dimethyldioctadecyl ammonium bromide (DOAB) film at pyrolytic graphite (PG) electrode. Electrochemical experiments revealed that Hb in DOAB film exhibited a pair of well-defined, quasi-reversible cyclic voltammetric peaks at about -0.160 V versus saturated calomel electrode (SCE) in pH 5.0 buffer, characteristic of the heme Fe(III)/Fe(II) redox couple of Hb. The electron transfer (eT) rate between Hb and the PG electrode was 0.10 s(-1). Positions of the Soret absorbance band indicated that the Hb retained its secondary structure and was similar to its native state. Furthermore, the Hb in DOAB film acted as a biological catalyst towards the reduction of nitric oxide (NO). The voltammetric response of NO at the Hb-DOAB modified electrode could be used to determine the concentration of NO in solution.