Porous N, C co-doped Co3O4 nanozyme with efficient oxidase-like activity for colorimetric detection of magnesium ascorbyl phosphate.

Nanozymes have been widely applied in the field of biosensing due to their enzyme-like catalytic activity and unique properties of nanomaterials. The activity of nanozymes is a key factor influencing sensor performance including detection sensitivity and analysis time. Therefore, developing new strategies to effectively improve the catalytic performance of the nanozyme is highly anticipated. This study takes Co3O4 nanozyme as an example, using low-cost and enzyme-free ovalbumin (OVA) as the template, generates additional pore structures within metal-organic frameworks, thereby increasing surface area and accelerating mass transfer rates. Meanwhile, OVA serves as both the nitrogen and carbon sources to promote electron transfer and further regulate the activity of nanozyme. Based on the above strategies, a N/C-Co3O4 nanozyme with efficient oxidase-like activity was successfully synthesized and applied in colorimetric detection of magnesium ascorbyl phosphate. The developed sensing system exhibited linear response across concentrations ranging from 0.50 to 70 μM, with calculated detection limit of 0.36 μM. These results demonstrate an innovative approach for regulating nanozyme activity through the integration of multiple methodological strategies.