Fig. 4: A multicolour fluorescence system controlled by tailoring the solvent composition.
a The optical features of the emissive compound PY16 monitored by fluorescence spectroscopy upon increasing the water content (from blue to orange), λex = 380 nm. b Recorded fluorescence intensity changes in the excimer emission peak (600 nm) with different water fractions. c CIE 1931 chromaticity diagram of compound PY16 with a steadily increasing water fraction. Inset: fluorescence images of PY16 in DMSO/H2O mixtures with different water fractions under UV light exposure, λex = 380 nm. d A schematic illustration of the information encryption-decryption process. e Fluorescence images of multiple pieces of information made from PY16 solution and written by adding water.
