Synergistically catalytic nanozymes based on heme-protein active site model for dual-signal and ultrasensitive detection of H_2O_2 in living cells

摘要

Herein, a peroxidase-like nanozyme (FeP-pSC_4-AuNPs), two-dimensional nanonetwork, was developed by a cationic metalloporphyrin (FeP) and supramolecular-modified gold nanoparticles (pSC_4-AuNPs) via the self-assembled method in aqueous solution. It involved the synergistically catalytic effects of the nanomaterials and the structural mimic of a heme-protein active site. The host-guest recognition of the ordered assembly was studied by molecular docking, proving a favorable interaction between the supramolecular and FeP. The nanozyme showed a highly catalytic activity with the increase of 3.3 and 2.7 times compared to that of pSC_4-AuNPs and FeP respectively. The mechanisms were explained by the heme-protein active site model, electron transfer promotion effect of AuNPs to FeP, and two-dimensional morphology. It was also robust to a wide range of pH, temperature, and storage conditions. Accordingly, the nanozyme was applied to the colorimetric and electrochemical bioassays for in situ detection of H_2O_2 in living cells, demonstrating the satisfactory sensitivity. As a result, this study achieved the ordered fabrication of a nonozyme with the synthetic simplicity and superior catalytic performance, and will facilitate the researches on the development, rational design, and bioassay applications of nanozymes.