Fig. 5: Temperature-dependent Raman spectroscopy of amino acids and phosphorescence spectroscopy of SNI-doped amino acid samples.
a Temperature-dependent Raman spectra of alanine in water, [Ala] = 0.50 M, λex = 532 nm. b Steady-state (dashed line) and delayed emission (solid line) spectra of SNI in solid-state amino acids at 77 K. From top to bottom: SNI@Leu, SNI@Ile, and SNI@Glu, SNI/amino acids (mass ratio) = 1/500, λex = 365 nm, delay time = 3 ms. Inserts: stick-and-ball chemical structures of related amino acids. SEM images of freeze-dried aqueous solutions of leucine (c), isoleucine (d), and glutamic acid (e), illustrating variations in morphologies and surface structures across different amino acids, [amino acids] = 166.8 mM.
