Single-holed cobalt - nitrogen - carbon hollow structure with oxidase-mimicking activity for the chemiluminescence determination of β - galactosidase activity.

A single-holed cobalt - nitrogen - carbon (Co - N - C) hollow structure nanozyme has been fabricated by in situ growth of zeolitic imidazolate framework (ZIF - 67) on the polystyrene (PS) sphere and following treatment by high-temperature carbonization. The Co - N - C nanostructure mimics the activity of oxidase and can activate O into reactive oxygen species (ROS), giving a remarkable enhancement on the chemiluminescence (CL) signal of luminol - O reaction. The Co - N - C oxidase mimic has further been exploited in the biosensing field by the determination of the activity of β - galactosidase (β - gal). The CL method for β - gal activity has a linear range of 0.5 mU·L to 5.0 U·L, a detection limit of 0.167 mU·L, and the precision of 3.1% (5.0 U·L, n = 11). This method has been employed to assess inhibitor screening of β - gal and determine activity of β - gal in spiked human serum samples.