Synthesis of ruthenium‐based metal ionic liquid polymer microspheres as an artificial enzyme for colorimetric detection of prochloraz residues in strawberries

Metal nanomaterial as artificial enzyme has high oxidase‐like activity, good stability, and low cost. The ruthenium‐based salicylic acid vinyl imidazole ionic liquid is subjected to radical polymerization to obtain ruthenium‐based ionic liquid polymer microspheres. The oxidative activity‐like artificial enzyme was synthesized by reducing the ruthenium‐based ionic liquid polymer microspheres with sodium borohydride. The research shows that the artificial enzyme based on ionic liquid polymer microspheres has excellent dispersibility, the average particle size is 1 μm, and the ruthenium are distributed on the surface of the polymer microspheres, showing high oxidase‐like activity. Based on the inhibitory effect of prochloraz on the artificial enzyme activity of ruthenium‐based ionic liquid polymer microspheres, a colorimetric detection method for the determination of prochloraz was established. The presence of prochloraz will inhibit the activity of the artificial enzyme of the ruthenium‐based ionic liquid polymer microspheres to promote the oxidation of 3,3′,5,5′‐Tetramethylbenzidine (TMB) to blue products, resulting in decrease in the absorbance of the TMB oxidation product, and the absorbance of the reaction system varies with the concentration of prochloraz between 0.01 and 100 μM increased and decreased linearly with a detection limit of 8 nM. The detection method is simple and quick, and can be used for the rapid determination of prochloraz residues in strawberries.