Simultaneous detection of fumonisin B ₁ and ochratoxin A using dual-color, time-resolved luminescent nanoparticles (NaYF ₄ : Ce, Tb and NH ₂ -Eu/DPA@SiO ₂ ) 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. [Figure not available: see fulltext.].