Refractometric sensing with fluorescent-core microcapillaries
Refractometric sensing with fluorescent-core microcapillaries
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DOI：
10.1364/oe.19.021540
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发表时间：
2011-10-24
期刊：
影响因子：
3.8
通讯作者：
Meldrum, A.
中科院分区：
文献类型：
--
作者：
Manchee, C. P. K.;Zamora, V.;Meldrum, A.
电容器是一种很有前途的微流体折射率传感器结构。我们展示了一种基于回音壁模式（WGM）共振的毛细管型荧光芯微腔传感器。该装置由具有涂覆在通道表面上的荧光硅量子点（QD）层的微毛细管组成。量子点层的高有效折射率限制了毛细管通道附近的电场，并导致荧光光谱中WGM共振的发展。将由溶解在水中的蔗糖组成的溶液泵送通过毛细管，同时用光谱仪测量荧光WGM。该装置的折射灵敏度为9.8 nm/RIU（对于更高的溶液折射率，可达13.8 nm/RIU），最大检测限为7.2 x 10（-3）RIU。模拟毛细管结构内部的场，其类似于分层中空环谐振器，表明通过优化QD膜厚度可以实现高达100 nm/RIU的灵敏度和低至类似于10（-5）RIU的检测限。(C)2011年美国光学学会
Capillaries present a promising structure for microfluidic refractive index sensors. We demonstrate a capillary-type fluorescent core microcavity sensor based on whispering gallery mode (WGM) resonances. The device consists of a microcapillary having a layer of fluorescent silicon quantum dots (QDs) coated on the channel surface. The high effective index of the QD layer confines the electric field near the capillary channel and causes the development of WGM resonances in the fluorescence spectrum. Solutions consisting of sucrose dissolved in water were pumped through the capillary while the fluorescence WGMs were measured with a spectrometer. The device showed a refractometric sensitivity of 9.8 nm/RIU (up to 13.8 nm/RIU for higher solution refractive index) and a maximum detection limit of similar to 7.2 x 10(-3) RIU. Modeling the field inside the capillary structure, which is analogous to a layered hollow ring resonator, shows that sensitivities as high as 100 nm/RIU and detection limits as low as similar to 10(-5) RIU may be achievable by optimizing the QD film thickness. (C) 2011 Optical Society of America