Turn-on colorimetric detection of hydroquinone based on Au/CuO nanocomposite nanozyme

CuO nanorods bearing Au nanoparticles (Au/CuO nanocomposites) were prepared by a solution-phase synthesis and exhibited efficient hydroquinone (HQ)-oxidase activity with good specificity. The Au/CuO nanocomposites effectively catalyzed the oxidation of colorless HQ to brown benzoquinone with an absorbance maximum at 376 nm but did not catalyze the conversions of catechol or resorcinol. Kinetic studies indicated that the Au/CuO nanocomposites exhibited a strong affinity for HQ, with a Michaelis-Menten constant of K-m = 0.33 mM. Owing to the high catalytic activity and specificity, a strong color was observed at low concentrations of HQ. Quantitative measurement of HQ was performed via colorimetric analysis, which yielded a detection limit of 3 mu M with a linear range of 5-200 mu M. This colorimetric sensor was successfully applied to an HQ assay of real water samples with satisfactory results.

Automated summary

Au/CuO nanocomposites prepared by solution-phase synthesis demonstrated efficient hydroquinone (HQ)-oxidase activity and good specificity. The nanocomposites exhibited a strong color reaction with HQ, allowing for quantitative measurement via colorimetric analysis. The sensor was successfully applied to the determination of HQ in real water samples.