Peroxidase model electrodes: heme peptide modified electrodes as reagentless sensors for hydrogen peroxide.
A peroxidase model electrode was devised for reagentless sensing of hydrogen peroxide (H2O2). A small model molecule, which mimics the vicinity of the reaction center of a redox enzyme, can communicate electrochemically with an electrode. Heme nonapeptide (MW congruent to 1600) having peroxidase activity was adopted as a peroxidase model compound and was covalently immobilized on a tin oxide (SnO2) electrode as a roughly monomolecular layer. The modified electrode thus obtained responded to H2O2 at concentrations down to 10(-6) M without electron mediator or promoter, at a mild potential of +150 or +300 mV vs Ag/AgCl. In a batch system, the response reached a steady state in a few seconds. Measurements were possible also in a flow system with an assay time of 0.5-1.0 min/sample. The steady-state response of the electrode was kinetically analyzed.
Tatsuma
T
T
Institute of Industrial Science, University of Tokyo, Japan.
Watanabe
T
T
D015374:Biosensing Techniques; D004563:Electrochemistry; D004566:Electrodes; D004800:Enzymes, Immobilized; D006418:Heme / Q000737:chemistry; D006801:Humans; D006861:Hydrogen Peroxide / Q000032:analysis*; D010455:Peptides / Q000737:chemistry; D010544:Peroxidases
D004800:Enzymes, Immobilized; D010455:Peptides; D006418:Heme; D006861:Hydrogen Peroxide; D010544:Peroxidases