Pyrene-based fluorescent molecularly imprinted polymer for the rapid and selective detection of oxytetracycline based on the inner filter effect

-allyl-4-(pyren-1-yl) butanamide (Al-Py), a new alkenyl functional monomer, was synthesized from 1-pyrenebutyric acid as the raw material through a simple synthesis process. Py-FMIP was then obtained with Al-Py as a functional monomer and OTC as a template molecule. The absolute fluorescence quantum yields of Al-Py and Py-FMIP were 74.05% and 69.27%, respectively, suggesting high fluorescence performances of the two materials. The fluorescence of Py-FMIP was strongly quenched by OTC through the inner filter effect. The prepared Py-FMIP sensor responded to OTC within 1 min, with a linear detection range of 0.5-150 µM, and its detection limit was 0.05 µM (S/N = 3). The prepared Py-FMIP sensor also exhibited notable selectivity toward OTC. The recoveries of the Py-FMIP fluorescent sensor ranged from 96.37% to 104.60% in milk and tap water, with relative standard deviations lower than 5.13%.