Ultrasonic synthesis of nano-PrO(1.8) as nanozyme for colorimetric determination of trans-resveratrol

In this study, nano-PrO(1.8) were synthesized successfully in ionic liquids (ILs) as template assisted ultrasonic irradiation method. Various precipitating agents and different types of ILs were investigated to determine their respective effects on the morphology of the end products. Using hydrazine hydrate as a precipitating agent and 1-carboxymethyl-3-methylimidazolium chloride as a template, spherical structure with an average diameter of 250 nm was obtained. It is worth noting that the prepared material exhibits high peroxidase-like activity and weak oxidase activity. Then, the catalytic oxidation capacity of the nano-PrO(1.8) was evaluated by the peroxidase substrate 3,3′,5,5′-tetramethylbenzidine (TMB). The colorless of TMB can be converted into blue oxidized TMB (oxTMB) in the presence of nano-PrO(1.8), but trans-resveratrol inhibited its peroxidase-like activity and weakened the blue color. Hence, we developed a sensitive, selective and simple colorimetric method for trans-resveratrol detection using nano-PrO(1.8) as peroxidase-like enzyme. A linear relationship was found in the range of 0.30 µM–16 µM trans-resveratrol with the detection limit of 0.29 µM. Satisfactory results were achieved when the method was submitted to the determination of trans-resveratrol in white wine samples.