Ru induced charge redistribution of MnO2 spheric nanozyme boosted hydrogen sulfide selective detection and cystathionine γ-lyase activity sensitive evaluation

Designing high-performance nanozymes to mimic natural enzymes for the ultrasensitive detection of biomarker is still a great challenge due to the insufficient catalytic capability of traditional nanozymes. Herein, a novel Ru cluster anchored MnO2 spheric nanozyme (Ru/MnO2) is designed and developed. The rationally designed Ru/ MnO2 displays excellent inherent POD-mimic catalytic capability. Density functional theory and XPS results demonstrates that the charge redistribution of Ru and Mn is the main factor for the improvement of the POD- mimic catalytic activity. Subsequently, the POD-mimic catalytic mechanism of Ru/MnO2 is also confirmed. With help of the excellent POD-mimic activity of Ru/MnO2 nanocatalysts and the significant improvement increased inhibitory action with H2S in formation of Ru-S due to the reduction of electrons around ruthenium, an ultrasensitive, selective, fast, and simple assay has been established, boosting H2S and cystathionine gamma- lyase (CSE) portable detection. Furthermore, the assay has been utilized to demonstrate within liver cancer cells and human colon cancer tissue in vivo, which holds great opportunity for colorimetric clinical monitoring of colon cancer with boosted sensitivity, thereby improving the survival rate of patients.