Surface-enhanced　Raman　scattering　(SERS)　is　a　rapid　and　nondestructive　spectroscopic　method　for　trace　detection.　The　enhancement　based　on　both　electromagnetic　and　chemical　mechanism　requires　the　molecules　to　be　in　close　contact　with　the　SERS-active　material.　Therefore,　it　is　difficult　to　detect　trace　amounts　of　molecules　in　liquid　directly.　In　this　paper,　graphene　oxide　(GO)　and　Ag　nanoparticles　(AgNPs)　are　uniformly　modified　on　the　inner　wall　of　the　capillary.　GO　can　provide　chemical　enhancement　by　adsorbing　the　analyte　onto　its　flat　surface　and　producing　efficient　charge　transfer　resonance　with　the　analyte.　AgNPs　can　provide　strong　localized　surface　plasmon　resonance　for　electromagnetic　enhancement,　while　capillary　can　shorten　the　molecular　enrichment　time　and　provide　long　light-analyte　interaction　length.　The　synergism　of　GO,　AgNPs,　and　capillary　makes　the　optofluidic　platform　have　the　ability　of　ultrasensitive　and　real-time　detection.　The　detection　limit　of　Rhodamine　6G　and　thiram　is　as　low　as　10(-12)　and　10(-10)　M,　respectively,　and　the　enhancement　factor　is　as　high　as　0.9　x　10(10)　and　10(8),　which　indicates　that　the　SERS-active　capillaries　have　great　potentials　in　real-time　ultratrace　detection　of　water　environment　pollutants.