A Significant Fluorescent Aptamer Sensor Based on Carbon Dots and Graphene Oxide for Highly Selective Detection of Progesterone.

In this paper, a fluorescent aptamer sensor was constructed based on the carbon dots (CDs) and graphene oxide (GO). This sensor combines the excellent fluorescence performance of CDs with the high specificity of aptamer, which can detect progesterone (P 4 ) with high sensitivity and selectivity. In the absence of P 4 , the CDs-aptamer system and GO form a fluorescence resonance energy transfer process (FRET), which quenches the fluorescence of the CDs. When P 4 is added, the aptamer specifically binds to it, resulting the fluorescence of the CDs is recovered. At optimal conditions, the fluorescence intensity recovered by the CDs has a linear relationship with the concentration of P 4 in the range of 0.1-120 nM and the detection limit is 3.3 × 10 -11 M. Besides, the sensor has satisfactory detection results of P 4 in milk, indicating that constructed method has enormous potential for application in food safety.