A novel graphene oxide-based aptasensor for amplified fluorescent detection of aflatoxin M1 in milk powder

In this paper, a rapid and sensitive fluorescent aptasensor for the detection of aflatoxin
M1 (AFM1) in milk powder was developed. Graphene oxide (GO) was employed to quench the
fluorescence of a carboxyfluorescein-labelled aptamer and protect the aptamer from nuclease cleavage.
Upon the addition of AFM1, the formation of an AFM1/aptamer complex resulted in the aptamer
detaching from the surface of GO, followed by the aptamer cleavage by DNase I and the release
of the target AFM1 for a new cycle, which led to great signal amplification and high sensitivity.
Under optimized conditions, the GO-based detection of the aptasensor exhibited a linear response to
AFM1 levels in a dynamic range from 0.2 to 10 g/kg, with a limit of detection (LOD) of 0.05 g/kg.
Moreover, the developed aptasensor showed a high specificity towards AFM1 without interference
from other mycotoxins. In addition, the technique was successfully applied for the detection of AFM1
in infant milk powder samples. The aptasensor proposed here o ers a promising technology for food
safety monitoring and can be extended to various targets.