Self-assembled Cr2O3@nanogel/Au nanozymes to simulate peroxidase activity as a H2O2 sensor.

The low temperature solvothermal method synthesized Cr2O3 NPs has not only peroxidase activity, but also oxidase activity. Then, the oxidase activity of Cr2O3 NPs is effectively shielded by nanogel immobilization using three monomers acrylamide, NIPAAM (N-isopropylacrylamide) and MBA (N,N'-methylene bisacrylamide) in HEPES (4-(2-hydroxyerhyl)piperazine-1-erhanesulfonic acid) buffer. Ultimately, the enzymatic activity of Cr2O3@nanogel/Au is significantly enhanced after doping Au NPs by SERS (Surface Enhanced Raman Spectroscopy) evaluation. A SERS strategy was proposed for the detection of H2O2 by Cr2O3@nanogel/Au. The linear range was 10-8 mol·L-1-10-1 mol·L-1.