화학공학소재연구정보센터
Inorganic Chemistry, Vol.59, No.24, 18384-18395, 2020
Hg2+ Significantly Enhancing the Peroxidase-Like Activity of H2TCPP/ZnS/CoS Nanoperoxidases by Inducing the Formation of Surface-Cation Defects and Application for the Sensitive and Selective Detection of Hg2+ in the Environment
Exploring excellent peroxidase mimics with enhanced peroxidase-like activity is important to the construction of a fast, low-cost, and convenient colorimetric sensing platform for heavy ions. In this work, 5,1 0,1 5,20-tetrakis(4-carboryphenyl)porphyrin (H2TCPP) was first used to modify ZnS/CoS and make it show better peroxidase-like activity. The metal-cation vacancies generated by He contacting H2TCPP/ZnS/CoS further stimulate the catalytic activity. It is reported that the addition of Hg2+ usually causes a decrease of the peroxidase-like activity of metal sulfides. Oppositely, in our work, He can trigger the colorimetric signal amplification because of lots of metal-cation vacancies generated on the surface of the nanocomposites (bimetallic sulfides). The peroxidase-like activity of ZnS/CoS was evaluated by virtue of the chromogenic substrate 3,3,5,5-tetramethyl- benzidine (TMB) from colorless to blue in 3 min. The enhanced catalytic activity of H2TCPP/ZnS/CoS was attributed to lots of active sites from the metal-cation defects on the surface of H2TCPP/ZnS/CoS as well as the synergistic effect of porphyrin molecules and ZnS/CoS. The adsorption behavior of H2O2 on the H2TCPP/ZnS/CoS surface with defects was studied by density functional theory calculation. Thus, a colorimetric sensing platform based on He trigger signal amplification has been successfully constructed, which can be used to sensitively and selectively determine Hg2+ in environmental samples.