Synergistically catalytic nanozymes based on heme-protein active site model for dual-signal and ultrasensitive detection of H2O2 in living cells

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 H2O2 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.

Automated summary

In this study, a peroxidase-like nanozyme was developed by self-assembly of a cationic metalloporphyrin and supramolecular-modified gold nanoparticles in aqueous solution, showing highly catalytic activity due to the synergistic effects of nanomaterials and structural mimic of a heme-protein active site. The nanozyme exhibited stability and superior catalytic performance under various conditions and was successfully applied in colorimetric and electrochemical bioassays for in situ detection of H2O2 in living cells.