Synthesis of a novel triphenylamine-based multifunctional fluorescent probe for continuous recognition applications

Abstract

In this paper, a novel fluorescent probe, TPA-PAT, with continuous recognition based on triphenylamine was designed, synthesized, and characterized by NMR, IR, and fluorescence spectrophotometry techniques. The research results showed that the probe could specifically recognize Cu²⁺ in DMSO/H₂O (99 : 1, v/v) with a detection limit as low as 0.40 μM and a coordination ratio of 1 : 2. On this basis, it was found that its complex TPA-PAT-Cu²⁺ could achieve a continuous progressive recognition of the anion S²⁻ and amino acids GSH, L-His, and L-Gly, while simultaneously showing high sensitivity for them with low detection limits of 25.7, 18.9, 21.7, and 45.9 nM, respectively. The probe had good reversibility and could be recycled. In addition, the probe TPA-PAT could simultaneously recognize Cu²⁺ and Hg²⁺ in acetone/H₂O (99 : 1, v/v) with detection limits of 0.16 and 0.20 μM, respectively, while their coordination ratios were 1 : 2. Similarly, its complex TPA-PAT-Hg²⁺ was able to continuously recognize the amino acids Cys and GSH with detection limits of 0.34 and 0.29 μM, respectively. It was also found that the probe and its complexes were able to be prepared for convenient dipstick applications, which could achieve a rapid fluorescence response to anions and amino acids and suggested its very good application prospects.