Development of a bioluminescent immunoassay based on Fc-specific conjugated antibody-nanoluciferase immunoreagents for determining aflatoxin B.

Aflatoxin B (AFB) is a potent carcinogen, and is among the most hazardous mycotoxins in agricultural products. Therefore, the development of sensitive and convenient detection methods for AFB is significant for food safety against mycotoxins. Herein, a bioluminescent enzyme immunoassay (BLEIA) was developed for ultrasensitive detection of AFB, 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, 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). 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.