A novel fluorescence nanosensor for Bi(Ⅲ) ions determination was developed based on the fluorescence resonance energy transfer from semiconducting polymer dots to methylene blue. The methylene blue attached to semiconducting polymer dots by electrostatic interaction, leading to fluo-rescence quenching of the fluorophores. When Bi ion was added, it coordinated more strongly with the carboxyl-functionalized semiconducting polymer dots than methylene blue, which made the meth-ylene blue detached from semiconducting polymer dots and interrupted luminescence energy transfer, allowing recovery of fluorescence. Such fluorescence responses can be used for well quantifying Bi ions in the range of 0-0. 5 μmol/L with a 16 nmol/L detection limit. The proposed sensing system has been successfully used for the assay of Bi ions in lake water.%基于半导体聚合物量子点和亚甲基蓝间的荧光共振能量转移构筑了一种铋离子荧光探针.亚甲蓝通过静电作用吸附到半导体聚合物量子点表面使其荧光发生猝灭.铋离子存在时,由于它与半导体聚合物量子点的结合力强于亚甲蓝,使体系的能量转移得到抑制,荧光恢复.在最优化条件下,线性范围为0~0.5μmol/L(R=0.9955),最低检出限为16 nmol/L.该方法成功用于湖水中的Bi3+测定,结果令人满意.
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