Molecularly imprinted ratiometric fluorescence detection of tetracycline based on its fluorescence enhancement effect caused by tungsten trioxide quantum dots

This paper reports a novel probe developed based on the tungsten trioxide quantum dots (WO3-x QDs) and molecularly imprinted polymers for the detection of trace tetracycline (TC) in the complex food matrix. Tungsten ion (W6+) in WO3-x QDs has a fluorescence enhancement effect on TC, and TC has a fluorescence quenching effect on WO3-x QDs. The blue emission of the WO3-x QDs (lambda(em) = 470 nm) as a reference and the yellow emission of the TC (lambda(em) = 550 nm) as a response were utilized for the ratiometric fluorescence detection. In order to improve its selectivity, the molecular imprinting technology was combined to construct molecularly imprinted ratiometric fluorescent probes (MIRFPs). Therefore, the MIRFPs can not only selectively detect TC, but also realize the visual detection from blue to yellow. Under the optimal conditions, the linear ranges of 0.01 similar to 10.0 mu mol/L and 20.0 similar to 80.0 mu mol/L were obtained with the limits of detection of 3.23 nmol/L and 6.37 mu mol/L, respectively. Furthermore, the MIRFPs had been successfully applied to the detection of TC in milk and eggs. The satisfactory recoveries were in the range of 92.7 similar to 102.9 % with relative standard deviations (RSD, n = 3) below 1.59 %. This work offers a good strategy for the detection of food hazards.

Automated summary

This study presents a novel probe based on tungsten trioxide quantum dots (WO3-x QDs) and molecularly imprinted polymers for the detection of trace tetracycline (TC) in complex food matrices. The WO3-x QDs exhibit fluorescence enhancement on TC, while TC quenches the fluorescence of WO3-x QDs. By utilizing the blue and yellow emissions of WO3-x QDs and TC, respectively, a ratiometric fluorescence detection method was developed. The incorporation of molecular imprinting technology improved the selectivity of the probe, allowing for both selective detection of TC and visual detection from blue to yellow.