We　report　a　new　SERS　sensor　based　on　the　hybridization　of　the　laser-induced　graphene　(LIG)　and　silver　nanoparticles　(AgNPs).　LIG　was　produced　by　direct　laser　writing　on　a　PI　film.　AgNPs　were　produced　on　the　LIG　surface　by　thermal　evaporation　of　silver.　The　porous-structured　LIG　layer　increases　largely　the　total　surface　area　of　the　substrate　and　supplies　delocalized　π　bonds　for　the　enhancement　of　the　adsorption　of　the　target　molecules　to　the　LIG　surface.　Furthermore,　LIG　also　provided　the　chemical　enhancement　mechanism.　The　high-density　hotspots　supplied　by　AgNPs　on　the　LIG　surface　in　such　a　hybrid　scheme　are　the　main　mechanism　for　the　SERS　sensing.　In　particular,　strong　surface　morphology　depending　on　the　Ag-deposition　thickness　and　deposition　rate　enables　modification　of　hydrophobicity　of　the　SERS　substrate,　which　gives　additional　channels　for　improving　the　SERS　performance.　Theoretical　analysis　on　the　distribution　of　the　optical　electric　field　facilitates　the　determination　of　the　optimized　Ag　thickness　and　the　deposition　rate.　These　multifold　enhancement　mechanisms　produced　a　SERS　enhancement　factor　of　3.19　×　105,　which　enables　high-sensitivity　detection　of　the　banned　dyes　(CV,　MG)　in　aquatic　products.　Strong　Raman　signals　were　detected　with　high　contrast　for　a　concentration　as　low　as　10−7　M.　This　sensor　also　has　potentials　for　on-site　detection　in　various　application　circumstances.　©　2024　Elsevier　B.V.