The special ink printed on the banknote; EUR, US$ and JPY emitts light by UV ray.
UV LED Flashlight has 45pcs UV LED which wavelength is 375nm. You can easily get high power UV ray and detect if a banknote is real one or not.
Don't look such a high power UV ray directly!
Detect urine,blood, and sperm next XD
bleachigo209 1 year ago