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

peer reviewedIn 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