A tetracycline-selective fluorescent biosensor using anthranilic acid immobilized on a glutaraldehyde-coated eggshell membrane

Abstract

Rapid and efficient detection of tetracycline (Tc) by immobilizing a fluorescent probe on a chemical sensor or biosensor is of great importance to scientific practice. In this study, an eggshell membrane (ESM) was modified for the quantification of Tc by immobilizing anthranilic acid (AA) on the membrane with glutaraldehyde as a cross-linking agent. The fluorescence emission peak of the ESM was effectively covered by AA as a fluorophore, and then the fluorescent intensity of AA could be efficiently quenched in the presence of Tc by the fluorescence inner filter effect (FIFE). The immobilization conditions (e.g. AA concentration and glutaraldehyde concentration) were optimized. The fluorescence sensor had a linear working range of 10 ng mL⁻¹ to 1 μg mL⁻¹, while the detection limit for Tc was 10 ng mL⁻¹. The proposed biosensor exhibited low detection limits, high sensitivity and selectivity, as well as excellent stability and regeneration. This biosensor was also successfully applied for the determination of Tc in food samples.