Fluorescent competitive aptasensor for detection of aflatoxin B1.

Aflatoxin B1 (AFB1) is one of the most commonly found mycotoxins in food commodities, particularly
cereals, oilseeds, spices and tree nuts. In the past decade, aptamers have come into limelight
and emerged as a new biosensing element replacing antibodies in various detection
formats. Herein we report a faster, more sensitive, high throughput method for the detection
of AFB1 using AFB1‐specific aptamers. The assay format was based on a competitive reaction
of the fluorescent tagged aptamer specific to AFB1 with the aflatoxin conjugate. Under optimal
conditions, a linear range of detection (50 ng to 50 pg) was achieved with a limit of detection
(LOD) of 10 pg/mL in the buffer system. Results of inter‐ and intra‐assay revealed that the assay
was repeatable with standard deviation in acceptable range. The assay was also validated in food
samples such as dried red chilies, groundnut and whole pepper with recovery in the range of 92 to
102% at 10 ng/mL and 100 pg/mL levels. The aptasensor assay was also compared with standard
analytical method of HPLC and was found to be more sensitive. This detection technique has the
potential to be developed into a biosensor platform for AFB1 detection.