Ru Atoms and Human Hemoglobin Confined in Nanoporous ZIF-67 as a Peroxidase-Mimicking Nanozyme for Cancer Identification

Precise diagnosis of a malignant tumor of a high degree is vital for highly effective prevention and the treatment of quality of human life, and abnormal levels of glucose or H 2 O 2 have been regarded as potential biomarkers for their functions in cancer origin, progression, and occurrence of metastasis. The levels of glucose and H 2 O 2 are remarkably different in cancer cells than in normal cells. Herein, an on-site colorimetric biosensor for cancer-related glucose and H 2 O 2 is developed utilizing a porous ruthenium (Ru) and hemoglobin human (HSA)-doped imidazole-based metal–organic framework (Ru 0.13 /HSA 0.06 /ZIF-67) as an outstanding peroxidase-mimicking nanozyme. Specifically, Ru 0.13 /HSA 0.06 /ZIF-67 nanohybrids are prepared by in situ doping of HSA into ZIF-67 followed by an ion-exchange process. Taking advantage of the unique structures of natural enzymes and interface engineering, HSA and Ru are confined in continuous porous ZIF-67 to largely expose the active sites for the created nanopores. The obtained distinct structure considerably boosts peroxidase-mimicking activity. The colorimetric assay reveals that the peroxidase-mimicking capability of the Ru 0.13 /HSA 0.06 /ZIF-67 nanohybrid is superior to that of Fe-based natural enzymes and other Ru catalysts. Moreover, a Ru 0.13 /HSA 0.06 /ZIF-67 nanozyme-based colorimetric assay is constructed for detecting glucose and H 2 O 2 via a visible signal readout. The developed toolkit for the preparation of Ru 0.13 /HSA 0.06 /ZIF-67 nanozymes with peroxidase-mimicking performance offers an avenue for rationally designing distinct nanozymes and has the potential perspectives for clinical transformation in colorimetric analysis.