We　here　report　a　novel　fluorescent　method　for　the　detection　of　melamine　based　on　the　high　fluorescence　quenching　ability　of　gold　nanoparticles.　The　fluorescence　was　significantly　quenched　via　fluorescence　resonance　energy　transfer　when　fluorescein　molecules　were　attached　to　the　surface　of　gold　nanoparticles　by　electrostatic　interaction.　Upon　addition　of　melamine,　the　fluorescence　was　enhanced　due　to　the　competitive　adsorption　of　gold　nanoparticles　between　melamine　and　fluorescein.　Under　the　optimum　conditions,　the　fluorescence　enhancement　efficiency　[(I　-　I0)/I0]　showed　a　linear　relationship　with　the　concentration　of　melamine　in　the　range　of　1.0　×　10-7　mol　L-1∼4.0　×　10-6　mol　L-1,　and　the　detection　limit　was　calculated　to　be　1.0　×　10-9　mol　L-1.　The　proposed　method　showed　several　advantages　such　as　high　sensitivity,　short　analysis　time,　low　cost　and　ease　of　operation.　©　2011　The　Royal　Society　of　Chemistry.