AgVO3类氧化酶对槲皮素的信号增强型比色传感研究

A Signal-Intensified Colorimetric Sensor for Quercetin with AgVO3 Nanozyme

摘要:

目前，纳米酶的设计合成及比色传感应用是分析化学领域的研究热点，开发一种具有高活性、良好稳定性、不依赖过氧化氢的单一类氧化酶活性材料是实现高效比色传感的关键。采用适合大规模制备的溶液共沉淀法，合成了长度为10—20 μm、直径为100—200 nm的AgVO₃纳米棒（AgVO₃ NRs）。研究发现，AgVO₃ NRs能催化无色的3,3′,5,5′-四甲基联苯胺（TMB）氧化生成蓝色产物oxTMB。机理研究发现，AgVO₃ NRs显示单一且高效的类氧化酶活性，并对不同底物具有广谱性。以TMB为底物时，底物诱导活化材料表面吸附的化学氧，并将其转化为超氧自由基（·O₂^-）。超氧自由基作为电子受体，将底物TMB氧化并触发显色反应，该过程近似为一级反应。当有槲皮素存在时，TMB的氧化得到促进，oxTMB浓度增加导致其吸光度显著上升，蓝色加深。基于该过程，构建了一种具有信号增强型“关-开”模式的槲皮素比色传感检测系统，即AgVO₃ NRs+TMB+槲皮素。研究结果表明，在25 ℃下、缓冲溶液pH=4条件下，槲皮素（浓度在0—1.0 μmol?L^-1）与oxTMB在652 nm处的吸光度呈良好的线性关系，检测限为11.82 nmol?L^-1。说明，AgVO₃ NRs是一种性能优良的类氧化酶材料，可实现多酚类化合物槲皮素的比色检测。本研究揭示了AgVO₃ NRs在化学分析检测、食品安全、生物医学领域的应用潜力。

Abstract:

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 （?O^2-）. 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.