具有双功能酶活性的Au/Cu多级组装颗粒的构建

Construction of Au/Cu hierarchically organized particles with dual-functional enzyme-like activity

纳米酶被定义为具有独特纳米结构和催化活性的模拟酶.受天然酶的启发,我们报道了一种具有仿多酚氧化酶和过氧化物酶活性的双功能Au/Cu多级组装颗粒(Hops).它不但能够快速氧化难降解的有毒酚类污染物,还可以用于灵敏检测生物供能物质.Au/Cu Hops纳米酶表现出优异的催化活性和可回收性,并且可在极端条件下保持稳定.值得注意的是,与天然漆酶相比,在相同质量浓度下,Au/Cu Hops纳米酶催化对苯二酚氧化反应具有更高的底物亲和力和6.37倍的Vmax.此外,基于Au/Cu Hops的仿过氧化物酶活性,我们构建了级联反应系统用于检测葡萄糖浓度,检测限低至5μmol L^(-1).最后,通过分子动力学模拟,我们证明了Cu-S簇在Au/Cu Hops表面形成双催化活性位点,并通过密度泛函理论计算揭示了纳米酶的催化途径.该工作对双功能纳米酶的构建和应用具有重要意义.

Nanozymes are defined as mimic enzymes with both unique nanostructures and catalytic activity.Inspired by natural enzymes,herein,we reported a dual-functional nanozyme of Au/Cu hierarchically organized particles(Hops)with excellent polyphenol oxidase-like(PPO-like)and peroxidase-like(POD-like)activities,which could rapidly oxidize refractory toxic phenolic pollutants and serve as a sensitive tool to detect biologically energy-supplying substances.Au/Cu Hop nanozymes exhibited excellent catalytic activity and recyclability and were stable under extreme conditions.Notably,Au/Cu Hop nanozymes had higher substrate affinity and 6.37 times higher Vmax compared with natural laccase for hydroquinone oxidation reaction at the same mass concentration.Furthermore,the cascade reaction system was constructed based on the POD-like activity of Au/Cu Hops to detect glucose concentration with a low detection limit of 5μmol L^(-1).Significantly,we demonstrated the formation of dual-catalytic active sites by Cu-S clusters on the surface of Au/Cu Hops by the molecular dynamics simulations and revealed the mimic enzyme catalysis pathway by the density functional theory calculation.This work has important implications for the construction and application of dual-functional mimetic enzymes.