Spontaneous detection of F- and viscosity using a multifunctional tetraphenylethene-lepidine probe: Exploring environmental applications

Abstract

Excessive fluoride ions (F？) in drinking water and food is harmful for human health and the environment. Therefore, a fluorescent probe tetraphenylethylene-quinoline (P-1) is developed with multiple sensing properties for the sequential detection of tert-butyldiphenylsilyl chloride (TBDS), F？, and viscosity. Sensor P-1 first recognized TBDS and then observed an intramolecular charge transfer process, which produced an intermediate sensor P-2 in addition to fluorescence quenching at 576 nm. Following this, P-2 revealed a concentration-related quantitative analysis by tracking F？ and reproducing sensor P-1 reversibly with the fluorescence amplification at 496 nm when the Sisingle bondN bond of P-2 was broken. A comparable sensing mechanism was noted in monitoring F？ and viscosity through a synthetically developed P-2 sensor. The characterizations (nuclear magnetic resonance-NMR, high resolution-mass-HR-MS, and high-performance liquid chromatography-HPLC) and density functional theory (DFT) confirmed the sensing mechanism of sensors P-1 and P-2. The proposed method was used to measure the viscosity of living cells and to measure F？ in food, water, and living cell samples. According to research results, quantitative emission characteristics versus F？ can offer insights into designing effective molecular probes with beneficial applications in healthcare and the environment.