Fig. 3. (a) Normalized UV-vis absorption spectra (left side) and PL spectra (right side) at room temperature in the mixed solvents for NapE4-5 (the volume ratio between PBS buffer solution and DMSO = 95 : 5, 10 μM, λex = 365 nm). (b) HOMO and LUMO distributions of NapE4 in the ground state. PL spectra of NapE4 (c) and NapE5 (d) in mixed DMSO/water with different water fractions (fw). (e) The plot of the relative emission intensity (I/I0) versus water fraction. I0 and I are the peak values of PL intensities of NapE5 in DMSO and DMSO/water mixtures, respectively. Inset: luminescence photograph.
