A molecular imprinting-based turn-on Ratiometric fluorescence sensor for highly selective and sensitive detection of 2,4-dichlorophenoxyacetic acid (2,4-D)

Abstract

a b s t r a c tA novel molecular imprinting-based turn-on ratiometric fluorescence sensor was constructed via a facile sol-gel polymerization for detection of 2,4-dichlorophenoxyacetic acid (2,4-D) on the basis of photoinduced electron transfer (PET) by using nitrobenzoxadiazole (NBD) as detection signal source and quantum dots (QDs) as reference signal source. With the presence and increase of 2,4-D, the amine groups on the surface of QDs@SiO 2 could bind with 2,4-D and thereby the NBD fluorescence intensities could be significantly enhanced since the PET process was inhibited, while the QDs maintained constant intensities. Accordingly, the ratio of the dual-emission intensities of green NBD and red QDs could be utilized for turn-on fluorescent detection of 2,4-D, along with continuous color changes from orange-red to green readily observed by the naked eye. The as-prepared fluorescence sensor obtained high sensitivity with a low detection limit of 0.14 μM within 5 min, and distinguished recognition selectivity for 2,4-D over its analogs. Moreover, the sensor was successfully applied to determine 2,4-D in real water samples, and high recoveries at three spiking levels of 2,4-D ranged from 95.0% to 110.1% with precisions below 4.5%. The simple, rapid and reliable visual sensing strategy would not only provide potential applications for high selective ultratrace analysis of complicated matrices, but also greatly enrich the research connotations of molecularly imprinted sensors.

An eco-friendly imprinted polymer based on graphene quantum dots for fluorescent detection of p-nitroaniline

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Design and application of novel molecular imprinting fluorescent sensors

“…将比率 荧光结合介孔硅制备技术, 得到的荧光表面印迹材 料的印迹识别位点不仅大部分位于材料的表面或附 近, 而且表面具有高度贯通的纳米孔结构, 从而大幅 提高对目标分子的传递能力, 增加质量传递速率, 这 对高度交联的印迹材料来说尤其重要. 前期实验结 果表明, 荧光印迹材料外表面高度贯通的孔结构, 使 其荧光性能在实际应用中具有更优的效果 [117] .…”

Development of a quantum dot molecularly imprinted polymer sensor for fluorescence detection of atrazine

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