A　simple　method　has　been　developed　for　the　preparation　of　silver　nanoparticles/carbon　based　quantum　dot　nano-hybrids　(AgNPs@CDs).　First,　the　small-sized　CDs　with　abundant　oxygen-containing　functional　groups　adsorbed　Ag+　ions　through　ion　exchange　or　coordination　reactions.　Then,　during　the　reaction　with　NaBH4,　the　Ag+　ions　were　reduced　to　AgNPs　while　the　oxygen-containing　functional　groups　were　partially　removed　from　the　CDs.　Thus,　CDs　were　coated　on　the　surfaces　of　the　resultant　AgNPs,　leading　to　the　formation　of　AgNPs@CDs.　The　residual　oxygen-containing　groups　on　the　CDs　made　the　obtained　AgNPs@CDs　possess　excellent　dispersivity　and　long-term　stability　in　water.　The　synthesized　AgNPs@CDs　showed　high　surface-enhanced　Raman　scattering　(SERS)　activity　and　provided　a　sensitive　SERS　sensing　ability　for　4-aminothiophenol,　with　a　wide　dynamic　range　from　1　×　10-10　to　1　×　10-5　M　and　a　low　detection　limit　(S/N　=　3)　of　5.0　×　10-11　M.　©　The　Royal　Society　of　Chemistry　2016.