Designing innovative nanozymes with satisfactory catalytic activity and biocompatibility through simple and inexpensive approaches and excavating their multifunctional applications have crucial value and significance for the development of nanozyme science. In this work, RuNPs with excellent oxidase (OXD)-mimetic and peroxidase (POD)-like activity were synthesized via simple one-pot solvothermal reaction and exploited for disease marker detection, elimination of cancer cells, and in vitro antibacterial. Based on the OXD-mimetic activity of RuNPs, a new colorimetric biosensor was ingeniously designed for α-glucosidase (α-Glu) activity determination and screening of its inhibitors. The detection range of α-Glu was 1-150 U L with the LOD of 0.19 U L, and IC of acarbose was calculated as 4.64 μM. Moreover, a RuNPs@SiO@GOx-based multifunctional nanoreactor that integrates biological enzyme and nanozyme was also designed and served as nanoprobe to develop a novel colorimetric/smartphone integrated sensing platform for one-step detection of blood glucose under near-neutral condition. Interestingly, RuNPs and RuNPs@SiO@GOx with multi-enzyme activity were also successfully utilized for anticancer cells and in vitro antibacterial respectively, which expands the application scenarios of nanozyme and provides inspiration for maximizing the exploitation of the functions of nanozyme.