Fluorescence detection of fluorine ions in biological fluids based on aggregation-induced emission

Abstract

Traditional chemical and biological sensors developed through aggregation-induced emission (AIE) are mainly based on “Turning on” pattern of fluorescence enhancement, which often has poor selectivity and can be easily interfered with by other substances. On this basis, an AIE-based tetraphenyl ethylene (TPE) derivative (TPE-COOH) was prepared in this study and aggregated by adding Al³⁺, so as to form the TPE-COOH/Al³⁺ polymer. TPE-COOH fluorescence was enhanced through AIE principle, thus realizing the “Turning on” state. F⁻ could bind to Al³⁺ after the addition of F⁻ ions which would result in the decomposition of TPE-COOH/Al³⁺ aggregate, dissolved state of TPE-COOH and gradual reduction of fluorescence intensity of the system, thus realizing “Turning off” state. Moreover, F⁻ ions in biological fluid were analyzed and detected through such AIE-based “Turning on-off” pattern. The linear range of this method for F⁻ detection was 3–12 μM and the detection limit was 0.9 μM.