A Signal-Intensified Colorimetric Sensor for Quercetin with AgVO3 Nanozyme
The design,synthesis,and colorimetric sensing applications of nanozymes are currently a research hotspot in the field of analytical chemistry.Developing a single oxidase-like active material with high activity,good stability,and independence from hydrogen peroxide is key to achieving efficient colorimetric sensing.Here,we synthesized AgVO3 nanorods(AgVO3 NRs)with a length of 10-20 μm and a diameter of 100-200 nm using a solution coprecipitation method suitable for large-scale preparation.The study found that these AgVO3 NRs can catalyze the oxidation of colorless 3,3′,5,5′-tetramethylbenzidine(TMB)to produce a blue product,oxTMB.Mechanistic studies revealed that these AgVO3 NRs exhibit a single and efficient oxidase-like activity with broad substrate specificity.When TMB is used as the substrate,the substrate induces the activation of chemically adsorbed oxygen on the material surface and converts it into superoxide radicals(·O2-).As an electron acceptor,the superoxide radicals oxidize the substrate TMB,triggering a colorimetric reaction,which is approximately a first-order reaction.In the presence of quercetin,the oxidation of TMB is promoted,and the increase in oxTMB concentration leads to a significant increase in its absorbance and a deeper blue color.Based on this process,we constructed a signal-enhanced"off-on"mode quercetin colorimetric sensing detection system:AgVO3 NRs+TMB+quercetin.In a buffer solution with pH=4 at 25℃,the concentration of quercetin in the range of 0-1 μmol∙L-1 showed a good linear relationship with the absorbance of oxTMB at 652 nm,with a detection limit of 11.82 nmol∙L-1.The research results show that AgVO3 NRs are a high-performance oxidase-like material that can achieve colorimetric detection of the polyphenolic compound quercetin,revealing its potential applications in chemical analysis and detection,food safety,and biomedicine.
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