Study and Application of HRP-like Catalyst Copper 2-Hydroxy-1-naphthaldehyde-2-aminothiazole {Cu II-(HNATS)2]

2-Hydroxy-1-naphthaldehyde-2-aminothiazole (HNATS) and its copper complex [CuII-(HNATS)2] had been synthesized. The complex of [CuII-(HNATS)2] was used to mimic the active group of horseradish peroxidase (HRP). The catalytic characteristics of this HRP-like catalyst in the H2O2-phenol- 4-AAP redox coupling reaction was studied, and the catalytic activity of [CuII-(HNATS)2] was compared with those of HRP and other Schiff base metal complexes. It was found that [CuII-(HNATS)2] exhibits a good catalytic activity and could be used as a novel catalyst in the determination of hydrogen peroxide (H2O2). The reaction mechanism, optimal experimental conditions and interferences of coexisting substances were discussed. Under the experimental conditions established, the linear relationship between the absorbance at 504 nm (A504) and H2O2 concentration was in the range of 5.6×10-6~1.1×10-4 mol/L, with a correlation coefficient (r) of 0.9990. The linear regression equation was A504 = 2540×C (mol/L) - 3.0×10-3 with a detection limit of 1.7×10-6 mol/L. In this paper, the complex [CuII-(HNATS)2] was applied successfully with catalytic spectrophotometric method to the determination of (-O-O-H) in polyethylene glycol.