A　sensitive　and　facile　quartz　crystal　microbalance　(QCM)　biosensor　for　glucose　detection　in　biological　fluids　was　developed　by　means　of　a　displacement-type　assay　mode　between　glucose　and　its　analogy　dextran　for　concanavalin　A　(ConA)　binding　sites　on　a　graphene-based　sensing　platform.　To　construct　such　a　displacement-based　sensor,　phenoxy-derived　dextran　(DexP)　molecules　were　initially　assembled　onto　the　surface　of　graphene-coated　QCM　probe　via　π-π　stacking　interaction,　and　ConA　molecules　were　then　immobilized　on　the　dextran　through　the　dextran-ConA　interaction.　Upon　addition　of　glucose,　the　analyte　competed　with　the　dextran　for　the　ConA,　and　displaced　it　from　the　QCM　probe,　leading　to　a　change　in　the　frequency.　Under　optimal　conditions,　the　frequency　change　relative　to　the　basic　resonant　frequency　was　proportional　to　glucose　concentration,　and　exhibited　a　dynamic　range　from　0.01　to　7.5.　mM　with　a　low　detection　limit　(LOD)　of　5.0　μM　glucose　(at　3　σ).　The　relative　standard　deviations　(RSDs)　were　below　6.2%　and　9.0%　for　the　reproducibility　and　selectivity　of　the　QCM　glucose　sensors,　respectively.　In　addition,　the　assay　system　was　evaluated　with　glucose　spiking　samples　into　the　distilled　water　and　blank　cattle　serum,　receiving　in　excellent　correlation　with　the　referenced　values.　©　2010　Elsevier　B.V.