– DMHBO+ is a cationic fluorophore that exhibits fluorescence upon binding to the chili aptamer (Kd = 12 nM), forming a complex that mimics red fluorescent proteins and is optimal for RNA imaging in cells. This compound serves as an excellent FRET donor to the rhodamine dye Atto 590, highlighting its utility in FRET-based analytical RNA systems. Key characteristics include excitation/emission maxima (λ) of 456/592 nm, a quantum yield of 0.1, and a stokes shift of 136 nm.