T	thymine
A	adenine
G	guanine
∆λ	wavelength deviation
DNA	deoxyribonucleic acid
GQ	G-Quadruplexes
Pcs	phthalocyanines
TO	thiazole orange
PBS	phosphate buffer solution
DC50	concentration of ligands required to decrease the fluorescence of the probe by 50%
IC50	concentration of the ligand required to reduce the cell viability by 50%
T2AG3	human telomeric sequence repeat—5′-TTA GGG-3′
T2G5T	tetramolecular G-quadruplex sequence—5′-TTG GGG T-3′
(G4T4G4)2	bimolecular G-quadruplex sequence—5′-GGG GTT TTG GGG-3′
AG3(T2AG3)3	unimolecular G-Quadruplex—5′-AGG GTT AGG GTTAGG GTT AGGG-3′
5GC	double strand DNA—5′-GCG CGC GCG C-3′
UV-Vis	UV-Visible spectroscopy
G4-FID	G-Quadruplex fluorescent intercalator displacement assay
CD	circular dichroism