An electrochemiluminescence(ECL) biosensor based on carboxyl functionalized poly［(9,9-dioctylfluorene-2,7-diyl)-co-(1,4-benzo-｛2,1′-3｝-thiadiazole)］polymer dots(PFBT-COOH) was constructed for the detection of glucose.The PFBT-COOH emitted a strong ECL signal without any exogenous coreactants,which could be effectively quenched by H2O2.In this work,PFBT-COOH was modified onto surface of glassy carbon electrode(GCE),and further cross linked with glucose oxidase(GOD) to obtain the biosensor,GOD/PFBT-COOH/GCE.With increase of glucose concentration in detection solution,amount of H2O2 generated by glucose in situ under the catalysis of GOD would increase,leading to a gradual weakening of ECL signal at the biosensor,thus achieving an accurate,quick and sensitive detection of glucose.The linear range of glucose was in the range of 1.0×10-7-3.0×10-3 mol/L,and the detection limit was 3.0×10-8 mol/L.The method was applid in the detection of glucose in serum samples with spiked recoveries of 985%-106%.Such a strategy provides a new idea for construction of enzyme sensor and a new method for glucose detection.