Geitenbeek Robin G, Vollenbroek Jeroen C, Weijgertze Hannah M H, Tregouet Corentin B M, Nieuwelink Anne-Eva, Kennedy Chris L, Weckhuysen Bert M, Lohse Detlef, van Blaaderen Alfons, van den Berg Albert, Odijk Mathieu, Meijerink Andries
Condensed Matter and Interfaces, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 1, 3584 CC Utrecht, The Netherlands.
BIOS, the Lab-on-a-Chip group, MESA+ Institute of Nanotechnology, University of Twente, P.O. box 217, Enschede, The Netherlands.
Lab Chip. 2019 Mar 27;19(7):1236-1246. doi: 10.1039/c8lc01292j.
Temperature control for lab-on-a-chip devices has resulted in the broad applicability of microfluidics to, e.g., polymerase chain reaction (PCR), temperature gradient focusing for electrophoresis, and colloidal particle synthesis. However, currently temperature sensors on microfluidic chips either probe temperatures outside the channel (resistance temperature detector, RTD) or are limited in both the temperature range and sensitivity in the case of organic dyes. In this work, we introduce ratiometric bandshape luminescence thermometry in which thermally coupled levels of Er3+ in NaYF4 nanoparticles are used as a promising method for in situ temperature mapping in microfluidic systems. The results, obtained with three types of microfluidic devices, demonstrate that temperature can be monitored inside a microfluidic channel accurately (0.34 °C) up to at least 120 °C with a spot size of ca. 1 mm using simple fiber optics. Higher spatial resolution can be realized by combining luminescence thermometry with confocal microscopy, resulting in a spot size of ca. 9 μm. Further improvement is anticipated to enhance the spatial resolution and allow for 3D temperature profiling.
芯片实验室设备的温度控制使得微流控技术在诸如聚合酶链反应（PCR）、用于电泳的温度梯度聚焦以及胶体颗粒合成等方面得到了广泛应用。然而，目前微流控芯片上的温度传感器要么探测通道外部的温度（电阻温度探测器，RTD），要么在使用有机染料的情况下，温度范围和灵敏度都受到限制。在这项工作中，我们引入了比率带形发光测温法，其中NaYF4纳米颗粒中热耦合的Er3+能级被用作微流控系统中原位温度测绘的一种有前景的方法。使用三种类型的微流控设备获得的结果表明，使用简单的光纤，在微流控通道内可以准确监测温度（0.34°C），最高可达至少120°C，光斑尺寸约为1mm。通过将发光测温法与共聚焦显微镜相结合，可以实现更高的空间分辨率，光斑尺寸约为9μm。预计进一步改进将提高空间分辨率并实现三维温度剖面分析。
