Different electrochemical behavior of adult and fetal hemoglobin at ionic liquid-carbon nanotube nanocomposite

摘要

The direct electrochemistry of human adult and fetal hemoglobin on the surface of nanocomposite containing the carboxylated multi-walled carbon nanotubes (MWCNTs) and a hydrophilic room temperature ionic liquid (RTIL) has been reported. The voltammetric results showed that both types of hemoglobins entrapped in RTIL-MWCNTs nanocomposite displayed a pair of well defined, quasi-reversible redox peaks, corresponding to the Fe(III)/Fe(II) redox couple of heme prosthetic group, with the formal potentials of -0.234 and -0.232 V (vs. Ag/AgCl) for human adult and fetal hemoglobin, respectively. Immobilized human fetal hemoglobin on RTIL-MWCNTs nanocomposite relative to immobilized human adult hemoglobin showed slight differences in reversibility, electron transfer rate and protein-substrate affinity toward hydrogen peroxide.