An optical aptasensor for aflatoxin M1 detection based on target-induced protection of gold nanoparticles against salt-induced aggregation and silica nanoparticles

Not only intoxications of aflatoxins are significant risk for human beings, but also; the contamination with these toxins affect the economy. Therefore, developing a rapid, precise and inexpensive determination method is vi-tally important. Here, a colorimetric aptasensor is introduced for the detection of aflatoxin M-1 (AFM(1)) based on the preservation of gold nanoparticles (AuNPs) against NaCl-induced aggregation by detaching of complementary strand of aptamer (CS) from the aptamer-modified streptavidin coated silica nanoparticles (SNPs) following the addition of target. So, the color of sample remains red. While, in the lack of AFM(1), salt-induced aggregation of AuNPs occurs and the color of sample becomes purple as the aptamer/CS (dsDNA)-modified SNPs is stable and CS cannot bind to AuNPs. The proposed aptasensor could detect AFM(1) in a linear dynamic range, 300-75,000 ng/L, with a detection limit of 30 ng/L. Also, the sensing method was effectively applied for AFM(1) recognition in milk samples. (c) 2020 Elsevier B.V. All rights reserved.

Automated summary

Aflatoxins pose significant risks to human health and the economy. Developing a rapid, precise, and inexpensive detection method is crucial. The colorimetric aptasensor based on gold nanoparticles can detect AFM(1) with high sensitivity and has practical applications in milk samples.