Sandwich-type colorimetric assay based on molecularly imprinted polymers and boronic acid functionalized Ni-Fe-MOF nanozyme for sensitive detection of allergen ovalbumin

Ovalbumin (OVA) is the main allergen in vaccines, and the sensitive detection of it could protect hypersensitive people. However, traditional detection technologies usually require natural antibodies, natural enzymes and long analysis time, which is not conducive to transportation, preservation and rapid detection. To solve this problem, the sandwich colorimetric strategy using Ni-Fe-MOF nanozyme linked with magnetic silicon dioxide surface molecularly imprinted particles (MSi-MIPs) are proposed for the first time to rapidly detect OVA in vaccines. The high sensitivity of this strategy depends on the sandwich structure of surface molecularly imprinted nano-particles, OVA and nanozymes. Ultra-thin Ni-Fe-MOF nanozyme exhibits large specific surface area and more peroxidase active sites. This has enabled the establishment of a specific and stable detection tool for OVA in vaccines. Under the optimal conditions, the assay exhibited a wide linear response range of 2.5 to 25 ng mL-1. The low limit of detection (1.02 ng mL-1) and the short analysis time (20 min) demonstrated the great potential of the strategy for OVA detection in vaccine samples.