An amperometric hydrogen peroxide sensor based on immobilization of hemoglobin in poly(o-aminophenol) film at iron-cobalt hexacyanoferrate-modified gold electrode.
A series of hybrid iron-cobalt hexacyanoferrate (FeCoHCF) films were electrodeposited on gold electrodes from solutions containing 6mM Fe(CN)(6)(3-) with different concentrations of Co(2+) and Fe(3+). FeCoHCF films deposited from solutions with different molar ratios of iron were studied by cyclic voltammetry, and their solid states were characterized by Fourier transform infrared spectroscopy. The kind of FeCoHCF film that deposited from a solution with a molar ratio of iron of 0.4 showed the largest response current to H(2)O(2) and was characterized by energy-dispersive X-ray spectroscopy. Therefore, the optimized FeCoHCF film was combined with nonconducting poly(o-aminophenol) (POAP) film that entrapped the hemoglobin (Hb) to construct hydrogen peroxide biosensor. The response current of the Hb/POAP/FeCoHCF/Au electrode (29.8 nA) was nearly 40 and was 1.5 times that of the Hb/POAP/Au (0.7 nA) and POAP/FeCoHCF/Au (20 nA) electrodes, respectively. The Michaelis-Menten constant of Hb in the Hb/POAP/FeCoHCF/Au film was 9.31 mM. These results show that the immobilized Hb in the Hb/POAP/FeCoHCF/Au film exhibits higher catalytic activity and larger response current to H(2)O(2) by the mediation of FeCoHCF. In addition, effects of applied potential, solution pH, and electroactive interferent on the response current of the Hb/POAP/FeCoHCF/Au electrode were investigated in detail.
Tao
Wenyan
W
State Key Laboratory of Chemo/Biosensing Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, People's Republic of China.
Pan
Dawei
D
Liu
Yingju
Y
Nie
Lihua
L
Yao
Shouzhuo
S
D000627:Aminophenols / Q000737:chemistry; D000818:Animals; D015374:Biosensing Techniques; D002417:Cattle; D003035:Cobalt / Q000032:analysis*; D003217:Conductometry / Q000379:methods*; D004566:Electrodes; D005290:Ferric Compounds / Q000032:analysis*; D006046:Gold / Q000737:chemistry*; D006454:Hemoglobins / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000032:analysis*; D011108:Polymers / Q000737:chemistry
D000627:Aminophenols; D005290:Ferric Compounds; D006454:Hemoglobins; D011108:Polymers; D003035:Cobalt; D006046:Gold; D006861:Hydrogen Peroxide