Simultaneous detection of fumonisin B1 and ochratoxin A using dual-color, time-resolved luminescent nanoparticles (NaYF4: Ce, Tb and NH2-Eu/DPA@SiO2) as labels

A rapid and highly sensitive time-resolved fluorescence (TRF)-based aptasensor for simultaneous recognition of mycotoxins ochratoxin A (OTA) and fumonisin B 1 (FB 1 ) was developed using multi-color, Ln 3+ -doped time-resolved fluorescence nanoparticles (TRF-NPs) (NaYF 4 : Ce, Tb and NH 2 -Eu/DPA@SiO 2 NPs) coupled with complementary strand DNA (cDNA) as luminescence probe and aptamers-conjugated amine-functionalized Fe 3 O 4 magnetic nanoparticles (MNPs) act as a capture probe. Under the optimized conditions, the time-resolved fluorescence intensities at 544 and 618 nm corresponded with Tb 3+ and Eu 3+ , respectively, were used to measure FB 1 ( Y  = 19,177.1 + (− 12,054.4) x , R 2  = 0.9917) and OTA ( Y  = 4138.8 + (− 11,182.6) x , R 2  = 0.9924), respectively. The limits of detection (LODs) for FB 1 and OTA were 0.019 pg mL −1 and 0.015 pg mL −1 , respectively, which were much lower than previously described methods for simultaneous recognition of mycotoxins OTA and FB 1 while detection range varied from 0.0001–0.5 ng mL −1 . This aptasensor was effectively applied to quantity FB 1 and OTA in maize samples and results were compared with ELISA method. This is the first reported time-resolved fluorescence (TRF)-based aptasensor to detect two agriculturally important toxins in the maize. The developed aptasensor has potential to be used for detection of toxins in food safety fields. Graphical abstract