G-quadruplex　(G4)　DNA　is　present　in　human　telomere　oligonucleotide　sequences.　Oxidative　damage　to　telomeric　DNA　accelerates　telomere　shortening,　which　is　strongly　associated　with　aging　and　cancer.　Most　of　the　current　analyses　on　oxidative　DNA　damage　are　based　on　ds-DNA.　Here,　we　developed　a　electrochemiluminescence　(ECL)　probe　for　enhanced　recognition　of　oxidative　damage　in　G4-DNA　based　on　DNA-mediated　charge　transfer　(CT),　which　could　specifically　recognize　damaged　sites　depending　on　the　position　of　8-oxoguanine　(8-oxoG).　First,　a　uniform　G4-DNA　monolayer　interface　was　fabricated;　the　G4-DNA　mediated　CT　properties　were　examined　using　an　iridium(III)　complex　[Ir(ppy)2(pip)]PF6　stacked　with　G4-DNA　as　an　indicator.　The　results　showed　that　G4-DNA　with　8-oxoG　attenuated　DNA　CT.　The　topological　effects　of　oxidative　damage　at　different　sites　of　G4-DNA　and　their　effects　on　DNA　CT　were　revealed.　The　sensing　platform　was　also　used　for　the　sensitive　and　quantitative　detection　of　8-oxoG　in　G4-DNA,　with　a　detection　limit　of　28.9　fmol.　Overall,　these　findings　present　a　sensitive　platform　to　study　G4-DNA　structural　and　stability　changes　caused　by　oxidative　damage　as　well　as　the　specific　and　quantitative　detection　of　oxidation　sites.　The　different　damage　sites　in　the　G-quadruplex　could　provide　detailed　clues　for　understanding　the　function　of　G4-associated　telomere　functional　enzymes.　©　2024　Elsevier　B.V.