For　the　first　time,　single-layer　carbon　dots　(CDs)　were　used　as　capping　agents　to　synthesize　cuprous　oxide　nanosheets　(Cu2O-NSs)　as　a　high-performance　surface　enhanced　Raman　scattering　(SERS)　substrate,　emphasizing　their　chemical　enhancement　mechanism.　The　Cu2O-NSs,　synthesized　using　single-layer　carbon　dots　as　capping　agents,　exhibit　uniform　morphology　and　remarkable　SERS　activity,　achieving　an　enhancement　factor　of　4.97　×　105　for　crystal　violet　under　532　nm　laser　excitation.　The　SERS　enhancement　is　primarily　attributed　to　photoinduced　charge　transfer　between　the　Cu2O-NSs　and　analyte　molecules,　as　confirmed　by　energy-level　alignment　studies.　The　substrate　demonstrates　excellent　signal　homogeneity,　batch-to-batch　reproducibility,　and　long-term　stability,　with　no　significant　signal　attenuation　over　60　days.　These　findings　underscore　the　potential　of　Cu2O-NSs　as　a　cost-effective　and　stable　SERS　substrate,　with　promising　applications　in　chemical　sensing　and　molecular　detection.　©　2025　The　Royal　Society　of　Chemistry.