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

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 H 2 O 2 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 H 2 O 2 . The catalytic mechanism of Pt/NiCo-LDH is due to OH radicals from decomposing of H 2 O 2 . Based on the high peroxidase mimetic activity of Pt/NiCo-LDH, a rapid and convenient colorimetric sensing platform for H 2 O 2 and glutathione has been successfully constructed. Under optional conditions, the colorimetric platform shows a sensitive response to H 2 O 2 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.