Gold　nanoclusters　(AuNCs)　have　shown　great　promise　for　in　vivo　imaging　because　of　their　definable　structure,　tunable　photoluminescence　(PL),　and　desired　renal　clearance.　However,　current　understanding　of　the　responsiveness　of　AuNCs　to　biological　substances　is　still　limited,　which　may　hamper　their　biomedical　applications.　Herein,　we　explore　the　oxidation　responsiveness　of　near-infrared　II　(NIR-II)　luminescent　AuNCs　capped　with　two　different　ligands,　which　can　be　optimized　for　high-efficiency　NIR-II　PL　imaging　of　mice　acute　kidney　injury　(AKI)　featuring　high-level　peroxynitrite　anions　(ONOO-).　We　found　that　in　the　presence　of　ONOO-,　N-acetylcysteine-capped　AuNCs　(NAC-AuNCs)　tended　to　be　oxidized　more　easily　than　that　capped　with　the　macromolecular　mercapto-β-cyclodextrin　(CDS-AuNCs),　resulting　in　the　aggregation　of　NAC-AuNCs　into　large-sized　assemblies,　which　was　not　observed　in　CDS-AuNCs.　The　oxidation-triggered　morphology,　composition,　and　NIR-II　PL　changes　in　NAC-AuNCs　were　then　systematically　studied.　We　finally　demonstrated　that　NAC-AuNCs　can　be　implemented　for　sensitive　NIR-II　PL　imaging　of　mice　AKI,　facilitated　by　the　synergetic　in　situ　AuNC　aggregation　and　decreased　glomerular　filtration　rate　(GFR)　in　the　injured　kidney,　which　outperforms　the　methods　solely　based　on　the　decreased　GFR　effect.　Therefore,　this　work　highlights　the　critical　significance　of　ligand　engineering　in　AuNCs　and　may　motivate　future　design　of　AuNCs　for　diverse　bioimaging　applications.　©　2023　American　Chemical　Society.