White peroxidase-mimicking nanozyme˗nanocarrier of enzyme labeled antibody to enhance catalytic performance and relieve color interference of immunoassay

Exploring a nanozyme as a nanocarrier for the enzyme-labeled antibodies (ELA) in the enzyme-linked immunosorbent assay (ELISA) is beneficial in improving the analytical performance of ELISA. Herein, a white Fe-based coordination polymer nanozyme (FCPN) was fabricated as a nanocarrier for the ELA to improve the catalytic activity and relieve the color interference of nanoprobes in ELISA. The proposed enhanced catalytic immunoassay (ECI) exhibits high analytical performance for the quantification of clenbuterol (CLL) in the detection range of 0.09–10 ng mL−1 with a limit of detection (LOD) as low as 0.09 ng mL−1, improving the detection sensitivity nearly 3.5 times compared with the conventional ELISA. Meanwhile, the usage of anti-CLL monoclonal antibodies in this proposed ECI was economizes by 6.7 times and the detection sensitivity was increased by nearly 4.5 times compared with our previous research. In addition, the detection sensitivity of the ECI using a white nanozyme as a nanocarrier is 2.3 times higher than using a blue Cu-based metal organic framework (Cu-MOF) nanozyme. Meanwhile, the applicability of the proposed ECI was successfully demonstrated by the detection of CLL in pork meat and pork liver with recoveries ranging from 92.51% to 110.16%.