New fluorescent light-up quinoxalines differentiate between parallel and nonparallel G-quadruplex topologies using different excitation/emission channels

In this study, new fluorescent quinoxalines were developed as G4 topology-selective probes. Among them, the most promising one could light up parallel G4s at two separate excitation wavelengths, exhibiting dual-channel emission, and light up nonparallel G4s at one excitation wavelength, showing mono-channel emission.