摘要
The crystal structures would directly affect the physical and chemical properties of the surface of the material,and would thus influence the catalytic activity of the material.α-MnO2,β-MnO2 andγ-MnO2 nanorods with the same morphology yet different crystal structures were prepared and tested as oxidase mimics using 3,3’,5,5’-tetramethylbenzidine(TMB)as the substrate.β-MnO2 that exhibited the highest activity had a catalytic constant of 83.75μmol·m^−2·s^−1,2.7 and 19.0 times of those ofα-MnO2 andγ-MnO2(30.91 and 4.41μmol·m^−2·s^−1),respectively.The characterization results showed that there were more surface hydroxyls as well as more Mn4+on the surface of theβ-MnO2 nanorods.The surface hydroxyls were conducive to the oxidation reaction,while Mn4+was conducive to the regeneration of surface hydroxyls.The synergistic effect of the two factors significantly improved the activity ofβ-MnO2 oxidase mimic.Usingβ-MnO2,aβ-MnO2-TMB-GSH system was established to detect the content of glutathione(GSH)rapidly and sensitively by colorimetry.This method had a wide detection range(0.11-45μM)and a low detection limit(0.1μM),and had been successfully applied to GSH quantification in human serum samples.
基金
This work was supported by the National Key R&D Program of China(No.2016YFA0202900)
China Postdoctoral Science Foundation(No.2018M642021)
the National Natural Science Foundation of China(No.21677095)
Minhang District Science and Technology Project of Shanghai(No.2019MH-MS02).
