A new fluorescent probe with large Stokes shift for selective and sensitive detection of arginine

The development of fluorescent probes for prompt and accurate arginine (Arg) detection with high selectivity and sensitivity is in great demand due to the critical roles and implications of Arg for health. In this paper, a new coumarin-derived fluorescent probe, CL, was designed and synthesized. It was efficient for the rapid and specific detection of Arg in MeCN/H₂O (6:4, v/v), with a low detection limit of 0.78 μM and a short response time of less than 10 s. Probe CL was stable at pH 3–10 and exhibited excellent anti-interference from competitive amino acids, including lysine, histidine, cysteine, homocysteine, glutathione, glycine, glutamic acid, valine, tyrosine, tryptophan, leucine, phenylalanine, aspartic acid and methionine. Density-functional theory (DFT) calculations investigated and verified the sensing mechanism. Considering that probe CL features multiple advantages, including high specificity, emission at a long wavelength of 642 nm with a massive Stokes shift of 272 nm, fast response and a broadly applicable pH range, this study provides a new idea for the development of susceptible and selective detection method for Arg.