BPCC

4-(2-Carboxyphenyl)-7-diethylamino-2-(7-diethylamino-2-oxochroman-3-yl)-chromylium perchlorate is an organic fluorescent dye that features a carboxyl functional group, with an excitation wavelength (λ ex) of approximately 650 nm and an emission wavelength (λ em) of around 690 nm [1].