Ratiometric fluorescent probe for tetracycline detection based on waste printing paper

Tetracycline (TC) represents a broad-spectrum antibiotic to treat bacterial infections. In this study, a ratiometric fluorescence (FL) probe was developed for the detection of TC in water samples by using waste printing paper extract as a FL indicator. In this ratiometric probe, the emission of printing paper extract at 436 nm gradually decreased and the emission of mixed solution at 538 nm significantly increased with the sequential addition of TC upon being excited at 390 nm, coupled with a remarkable FL color change from bright blue to faint yellow. Thus, a ratiometric F538 /F436 FL probe was created for TC detection by simply mixing the printing paper extraction and TC. Under the optimized conditions, the linear range from 1-100 μM and a detection limit of 0.48 μM (S/N = 3) for TC were obtained. Importantly, the FL probe can be easily prepared with rapid response, high sensitivity, and good selectivity. The application of the waste printing paper extract for the detection of TC in environmental water samples was demonstrated.