Novel triadimenol detection assay based on fluorescence resonance energy transfer between gold nanoparticles and cadmium telluride quantum dots

We developed a highly sensitive fluorescent assay based on fluorescence resonance energy transfer (FRET) between gold nanoparticles (AuNPs) and cadmium telluride (CdTe) quantum dots (QDs) for detection of triadimenol in tap water and agricultural irrigation water. The electrostatic interaction between the positively charged CdTe QDs and negatively charged AuNPs strongly quenched the fluorescence emission of CdTe QDs. In the presence of triadimenol, the strong electrostatic attraction between negatively charged AuNPs and positively charged triadimenol molecules rapidly induced the aggregation of AuNPs, blocking the FRET reaction and attenuating the quenched efficiency of CdTe QDs. The change of fluorescence intensity was linearly related to the concentration of triadimenol in the concentration range of 0.338–33.8 μM. The detection limit (S/N = 3) of the sensor was as low as 0.182 μM. The fluorescent sensor was successfully used to detect triadimenol in spiked water samples and gave good recoveries.