A　simple　method　for　one-step　synthesis　of　aggregated　gold　nanoparticles　(a-AuNPs)　using　single-layer　carbon　dots　(s-CDs)　as　the　capping　agents　has　been　proposed.　The　obtained　a-AuNPs　are　mainly　composed　of　several　spherical　AuNPs　of　20-25　nm　sized,　which　aggregate　to　form　nanogaps　of　similar　to　1　nm.　Furthermore,　the　obtained　aAuNPs　produce　a　strong　localized　surface　plasmon　resonance　(LSPR)　absorption　band　centered　at　around　640　nm,　which　is　quite　close　to　the　wavelength　of　the　commonly　used　633　nm　laser　in　surface　enhanced　Raman　scattering　(SERS).　Thus,　under　the　irradiation　of　633　nm　laser,　a　lot　of　electromagnetic　field　＂hot　spots＂　are　formed　at　around　the　nanogaps,　and　strong　SERS　activity　is　achieved.　The　obtained　a-AuNPs　are　dropped　on　tinfoil　wafers　to　fabricate　SERS　substrates,　which　show　the　advantages　of　high　sensitivity,　fast　response,　good　repeatability　and　satisfactory　stability.　On　the　basis,　a　sensitive　SERS　sensor　is　developed　to　detect　malachite　green　in　aquaculture　water,　with　a　low　detection　limit　of　1　x　10(-9)　mol/L.