High-sensitivity online detection for microfluidics via cavity ringdown spectroscopy
High-sensitivity online detection for microfluidics via cavity ringdown spectroscopy
复制标题
通过腔衰荡光谱对微流控进行高灵敏度在线检测
作者：
James D
我们报告的耦合腔衰荡光谱（CRDS）与微流控芯片制造使用快速成型方法，以证明高灵敏度，非接触式在线检测微流控。常规的紫外-可见吸收技术由于小的样品体积和短的路径长度而在很大程度上对微流体检测无效。光腔衰荡光谱中的多程吸收使有效吸收路径长度增加了几个数量级，从而提高了探测灵敏度。一个腔衰荡光谱仪，工作在一个单一的波长为532 nm的概念验证测量的目的，在这里提出的，已经开发了在线检测的聚合物/玻璃微芯片制作的正面光聚合。高灵敏度的吸收测量液体样品的体积从几十到几百纳升和吸收路径长度范围从几十到几百微米的演示。一系列的概念验证实验表明，该技术具有监测静态和随时间变化的分析物浓度的能力。首先，通过对高锰酸钾稀水溶液的吸收测量（532 nm处的自然吸收系数为（4805 ± 10）M−1 cm−1）进行三个标准偏差误差分析，估计系统的检测限。对于466 μm的光程，检测限为1.210 nM，对应于1.0 × 10−3 cm−1的吸收。通过监测以毫摩尔浓度存在的酚酞指示剂的吸收，对20 nL样品进行在线pH测量。最后，CRDS已被应用，第一次，在微流控芯片上监测化学反应动力学，跟踪著名的Belousov-Zhabotinsky反应的振荡周期。
We report the coupling of cavity ringdown spectroscopy (CRDS) with a microfluidic chip fabricated using a rapid prototyping method, in order to demonstrate high-sensitivity, non-contact online detection in microfluidics. Conventional UV-vis absorption techniques are largely ineffective for microfluidic detection due to the small sample volumes and short path lengths. The multipass absorption achieved in cavity ringdown spectroscopy increases the effective absorption pathlength by several orders of magnitude, and hence enhances the detection sensitivity. A cavity ringdown spectrometer, operating at a single wavelength of 532 nm for the purposes of the proof-of-concept measurements presented here, has been developed for online detection on a polymer/glass microchip fabricated by frontal photopolymerisation. High sensitivity absorption measurements on liquid samples with volumes of tens to hundreds of nanolitres and absorption pathlengths ranging from tens to hundreds of microns are demonstrated. A series of proof-of-concept experiments show that the technique has the ability to monitor both static and time-varying analyte concentrations. Firstly, the detection limit of the system is estimated from a three-standard-deviation error analysis of absorption measurements made on dilute aqueous solutions of potassium permanganate (natural absorption coefficient (4805 ± 10) M−1 cm−1 at 532 nm). The detection limit was found to be ∼210 nM for a 466 μm pathlength, corresponding to an absorption of 1.0 × 10−3 cm−1. Online pH measurements on a 20 nL sample are performed by monitoring the absorption of phenolphthalein indicator present at millimolar concentrations. Finally, CRDS has been applied, for the first time, to monitoring chemical reaction kinetics on a microfluidic chip, tracking the oscillation period of the well-known Belousov–Zhabotinsky reaction.
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影响因子：
2.9
作者：
Fletcher, PDI;Haswell, SJ;Zhang, XL
通讯作者：
Zhang, XL
DOI：
--
发表时间：
2002
期刊：
影响因子：
--
作者：
Shucheng Xu;G. Sha;Jinchun Xie
通讯作者：
Jinchun Xie
影响因子：
15
作者：
Song, H;Ismagilov, RF
通讯作者：
Ismagilov, RF
影响因子：
6.1
作者：
Neil, Simon R. T.;Rushworth, Cathy M.;Mackenzie, Stuart R.
通讯作者：
Mackenzie, Stuart R.
在纯液体腔中通过腔衰荡光谱提高 HPLC 吸收检测的灵敏度
DOI：
--
发表时间：
2006
期刊：
影响因子：
--
作者：
L. V. D. Sneppen;A. E. Wiskerke;F. Ariese;C. Gooijer;W. Ubachs
通讯作者：
W. Ubachs