Development of a bioluminescent immunoassay based on Fc-specific conjugated antibody-nanoluciferase immunoreagents...

Aflatoxin B₁ (AFB₁) is a potent carcinogen, and is among the most hazardous mycotoxins in agricultural products. Therefore, the development of sensitive and convenient detection methods for AFB₁ is significant for food safety against mycotoxins. Herein, a bioluminescent enzyme immunoassay (BLEIA) was developed for ultrasensitive detection of AFB₁, based on the novel Fc-specific antibody-nanoluciferase (Ab-Nluc) conjugates which were fabricated using an IgG-binding protein-assisted photo-conjugation strategy. In indirect competitive immunoassay format, the proposed BLEIA exhibited the detection limit of 0.0232 ng mL^-1, which was 37.4-fold lower than that obtained using the classical enzyme-linked immunosorbent assay (ELISA) based on Ab-horseradish peroxidase (Ab-HRP) chemical conjugates (0.868 ng mL^-1). Meanwhile, the BLEIA exhibited high accuracy and precision. Thus, the proposed Fc-specific Ab-Nluc conjugates-based BLEIA provides an ultrasensitive and reliable method for detecting toxins and has potential for use in food safety monitoring.