South China Sea Annual Meeting 2023 (SCSAM)

12 / 2023-07-23 11:27:30

Fluorescence Sensing of Ammonium in Water

Floorescence sensing,,Ammonium,Water

Ammonia nitrogen is one of the most important indicators of water pollution and quality, which plays an important role in the biogeochemical cycle. Ammonia nitrogen refers to a class of combined nitrogen that exists in the form of NH₃ or NH₄⁺. Their proportion depends on temperature, salinity and pH of water, which makes the complicated determination of ammonia nitrogen in water. In this study, the sensing research based on 5-aminofluorescein (AF) sol gel in ammonium determination. Fluorescein is one of the most important fluorescent materials, which are widely used in analytical detection and biological imaging. The work in this chapter finally selected AF as a fluorescence sensing reagent for ammonium sensing, and prepared the sol gel for ammonium sensing research by exploring three fluorescein as 5-aminofluorescein (AF), 5-carboxylfluorescein (CF), and fluorescein sodium salt (FS). Compared to AF powder, the quantum yield of AF sol gel increased from 1.52% to 2.34%. The experimental results show that this sensing material has good NH₄⁺ sensing performance: a linear fluorescence quenching response in the range of 0.08-1.0 mg/L at pH 8. The response time for the sensing is 10 minutes, and the detection limit is found to be 0.015 mg/L.