A novel fluorescence aptasensor based on mesoporous silica nanoparticles for selective and sensitive detection of aflatoxin B1

Abstract Based on the mesoporous silica nanoparticles (MSN), a novel, simple and label-free aptamer biosensor was designed for the detection of aflatoxin B 1 (AFB 1 ). Here, the aptamers were used as molecular recognition probes and “gated molecules” while Rh6G was loaded into the interior of the particles as the signal probe. In the absence of AFB 1 , the “gate” was closed to prevent the leakage of the signal probe because of the immobilization of aptamers on the surface of MSN-NH 2 . With the presence of AFB 1 , the “gate” could be opened to release the signal probe for the specifical binding of aptamers to AFB 1 . Our results showed that the fluorescence intensity was positively correlated with the concentration of AFB 1 (0.5–50 ng mL −1 ), with the detection limit as low as 0.13 ng mL −1 . What's more, this design provides a new approach for rapid, sensitive and selective detection based on aptamers and it could be applied to numerous other analytes if appropriate aptamers are available.