Fluorescence of Two Dyes
Two plastic cuvettes filled in with different solutions, the first containing Hoechst33342 and the second Propidium Iodide dyes, are simultaneously illuminated with two different lasers, operating at 375 nm and 488 nm. The Hoechst33342 dye shows greenish fluorescence with only the 375-nm excitation wavelength, while the Propidium Iodide dye shows red fluorescence only while illuminated by the 488-nm laser. The picture—a very simple demonstration of fluorescence, showing wavelength selectivity of materials—was taken with a Huawei smartphone during the experiments at the B-PHOT, Vrije Universiteit Brussel, Belgium.
—Tatevik Chalyan, B-PHOT Brussels Photonics Team, Vrije Universiteit Brussel, Belgium