Determination of acetic acid in enzymes based on the cataluminescence activity of graphene oxide-supported carbon nanotubes coated with NiMn layered double hydroxides.

A cataluminescence (CTL) method has been developed for the rapid determination of acetic acid in enzyme products. The NiMn LDH/CNT/GO was synthesized based on the nanohybridization of NiMn layered double hydroxide (NiMn LDH), carbon nanotubes (CNTs), and graphene oxide (GO). The composite has excellent CTL activity against acetic acid. It could be ascribed to the larger specific surface area and more exposure to active sites. NiMn LDH/CNT/GO is used as a catalyst in the CTL method based on its special structure and advantages. There is a linear relationship between CTL response and the acetic acid concentration in the range 0.31-12.00 mg·L -1 with the detection limit of 0.10 mg·L -1 . The developed method is rapid and takes only about 13 s. The method is applied to the determination of acetic acid in enzyme samples with little sample preparation. The result of the CTL method shows good agreement with that of the gas chromatography method. The proposed CTL method possesses promising potential in the quality monitoring of enzymes.