An aptamer fluorescent biosensor based on graphene oxide for the detection of sulfadiazine in Yangtze River water

Using 6-carboxyfluorescein (FAM)-labeled aptamer FAM-SDZ30-1 as the probe and graphene oxide (GO) as the fluorescence quenching agent，an aptamer fluorescence biosensor based on GO was constructed for detecting sulfadiazine (SDZ) residues in Yangtze River water. When the absence of SDZ in the solution，FAM-SDZ30-1 was adsorbed on the GO surface by π-π stacking. Due to the fluorescence resonance energy transfer，the fluorescence of FAM-SDZ30-1 was quenched by GO；When SDZ existed in the solution，FAM-SDZ30-1 combined with SDZ to form a complex，which could not be adsorbed on the GO surface，and the fluorescence of the solution remained unchanged. Under the optimal conditions，the fluorescence intensity of the aptasensor showed a linear relationship with the concentration of SDZ in the range of 25-625 ng/mL，with a correlation coefficient R2 of 0.9986，and the detection limit was 53.13 ng/mL. This method could be applied to detect SDZ residues in Yangtze River water. © 2024, Youke Publishing Co.,Ltd. All rights reserved.