Fast colorimetric sensing of H2O2 and glutathione based on Pt deposited on NiCo layered double hydroxide with double peroxidase-/oxidase-like activity

摘要

The Pt/NiCo layered double hydroxides nanocomposites (Pt/NiCo-LDH NCs) have been successfully prepared by a one-pot hydrothermal method. Pt/NiCo-LDH was demonstrated to possess an excellent peroxidase-like activity together with a weak oxidase-like activity, evaluating in virtue of rapid catalytic oxidization of 3, 3 ', 5, 5'-tetramethylbenzidine (TMB) by H2O2 into a blue oxidation product (oxTMB) only in 30 s. The short response time is very important for designing colorimetric sensors to realize real time detection. The catalytic behaviors of Pt/ NiCo-LDH followed the Michaelis-Menten kinetics, possessing a good affinity towards both TMB and H2O2. The catalytic mechanism of Pt/NiCo-LDH is due to (OH)-O-center dot radicals from decomposing of H2O2. Based on the high peroxidase mimetic activity of Pt/NiCo-LDH, a rapid and convenient colorimetric sensing platform for H2O2 and glutathione has been successfully constructed. Under optional conditions, the colorimetric platform shows a sensitive response to H2O2 and glutathione in the linear range of 10-90 mM and 50-500 mM with a limit of detection of 0.76 mM and 3.77 mM, respectively.