Aptamer based ratiometric determination of DON by exploiting the FRET between carbon dots and graphene oxide

A ratiometric aptasensor for deoxynivalenol (DON) detection was developed based on FRET between graphene oxide (GO) and carbon dots. Blue carbon dots, functionalized with aptamers, act as energy donors, while GO functions as the energy acceptor. In the absence of DON, the addition of GO quenches the fluorescence of the blue carbon dots, while the fluorescence of red carbon dots, used as internal reference signals, remains unchanged. When DON is introduced, the aptamer selectively binds to the target, increasing the distance between the donor and acceptor, disrupting FRET, and gradually restoring the blue fluorescence. The sensor demonstrated a strong linear relationship within the concentration range of 0.05–200 ng/mL of DON, with a detection limit of 14.7 pg/mL. The superior analytical performance and high sensitivity indicate the potential of the sensor for DON detection in real sample matrices.