Tetracycline Molecularly Imprinted Fluorescent Sensor Based on Tomato Stalk-Derived Carbon Dots

In this work, novel biomass-derived carbon dots (CDs) with superior fluorescent properties were prepared from tomato straws. A selective, eco-friendly tetracycline (TC) sensor was fabricated by immobilizing a SiO2 molecularly imprinted polymer (MIP) layer onto CDs, forming a CDs@SiO2-MIP composite. This sensor combined highly selective adsorption properties with the sensitivity of fluorescence detection, with the sensing mechanism stemming from the off-fluorescent signal after molecular imprinting specifically recognizing the target substance. Under optimal conditions, the sensor exhibited a linear response to TC concentrations ranging from 1.00 × 10−7 to 5.00 × 10−4 mol/L, with fluorescence intensity decreasing as concentration increased. The detection limit of TC was 9.33 × 10−8 mol/L. This work provides novel biomass-derived CDs and a simple molecularly imprinted fluorescence sensing method for the detection of environmental organic pollutants.