Silver amplified immunosensor via effective fluorogenic Ag + -imidazole aggregation for detection of AFB 1 .

Background: Cereals are susceptible to aflatoxin contamination during storage and transportation, which is highly carcinogenic and teratogenic, and seriously threaten human health. The accurate and rapid detection of total aflatoxin (including aflatoxin B1, B2, G1, and G2) is of great importance for food safety. Conventional fluorescence immunoassays have the advantage of being sensitive and fast; however, these methods can be affected by strong background and matrix interference. Therefore, the development of ultrasensitive, cost-effective, and interference rejection sensors for detecting aflatoxins in moldy grains is vital for food safety and human health.
Results: In this paper, a broad-spectrum aflatoxin monoclonal antibody was prepared by using hybridoma cell fusion technology. An aggregation-induced emission (AIE) based immunosensor via silver amplification coupled with a fluorogenic Ag ⁺  probe was established for AFB ₁ analysis. Silver nanoparticles are decomposed into numerous Ag ⁺  by H ₂ O ₂ , and then Ag ⁺ further specifically binds with imidazole-modified AIE molecules, improving the sensitivity and anti-interference ability of the method. The IC ₅₀ and IC ₁₅ of AIE-based immunosensor for AFB ₁ were 0.019 and 0.0014 μg/L, respectively, 2.3-fold and 5.8-fold higher than those of icELISA. The AIE-based immunosensor was also used to analyze AFB ₁ from actual cereal samples, with spiked recoveries ranging from 72.91 to 115.92 %. In addition, the method was used to detect total aflatoxins in moldy grains.
Significance: Based on the advantages of broad-spectrum aflatoxin monoclonal antibody, high-efficiency metal signal amplification, and functional AIE molecule, a sensitive, accurate, cost-effective, and time-saving method was developed for the analysis of total aflatoxins in cereals. Moreover, the proposed signal amplification strategy shows great potential for analyzing other trace-level small molecular pollutants.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
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