G‐Tetraplex‐Induced FRET within Telomeric Repeat Sequences Using PyA‐PerA as Energy Donor–Acceptor Pair

G‐tetraplex induced fluorescence resonance energy transfer (FRET) within telomeric repeat sequences has been studied using a nucleoside‐tethered FRET pair embedded in the human telomeric G‐quadruplex forming sequence (5′‐A GGG TT ^Py A GGG TT ^Per A GGG TTA GGG‐3′, Py=pyrene, Per=perylene). Conformational change from a single strand to an anti‐parallel G‐quadruplex leads to FRET from energy donor ( ^Py A ) to acceptor ( ^Per A ). The distance between the FRET donor/acceptor partners was controlled by changing the number of G‐quartet spacer units. The FRET efficiency decreases with increase in G‐quartet units. Overall findings indicate that this could be further used for the development of FRET‐based sensing and measurement techniques.