Micheal Raj Pushparani, Barbe Laurent, Andersson Martin, De Albuquerque Moreira Milena, Haase Dörthe, Wootton James, Nehzati Susan, Terry Ann E, Friel Ross J, Tenje Maria, Sigfridsson Clauss Kajsa G V
MAX IV Laboratory, Lund University Lund Sweden
Dept. Materials Science and Engineering, Science for Life Laboratory, Uppsala University Uppsala Sweden.
RSC Adv. 2021 Sep 7;11(47):29859-29869. doi: 10.1039/d1ra05270e. eCollection 2021 Sep 1.
Some of the most fundamental chemical building blocks of life on Earth are the metal elements. X-ray absorption spectroscopy (XAS) is an element-specific technique that can analyse the local atomic and electronic structure of, for example, the active sites in catalysts and energy materials and allow the metal sites in biological samples to be identified and understood. A microfluidic device capable of withstanding the intense hard X-ray beams of a 4th generation synchrotron and harsh chemical sample conditions is presented in this work. The device is evaluated at the -edges of iron and bromine and the -edge of lead, in both transmission and fluorescence mode detection and in a wide range of sample concentrations, as low as 0.001 M. The device is fabricated in silicon and glass with plasma etched microchannels defined in the silicon wafer before anodic bonding of the glass wafer into a complete device. The device is supported with a well-designed printed chip holder that made the microfluidic device portable and easy to handle. The chip holder plays a pivotal role in mounting the delicate microfluidic device on the beamline stage. Testing validated that the device was sufficiently robust to contain and flow through harsh acids and toxic samples. There was also no significant radiation damage to the device observed, despite focusing with intense X-ray beams for multiple hours. The quality of X-ray spectra collected is comparable to that from standard methods; hence we present a robust microfluidic device to analyse liquid samples using synchrotron XAS.
金属元素是地球上生命一些最基本的化学组成部分。X射线吸收光谱法（XAS）是一种元素特异性技术，它可以分析例如催化剂和能源材料中活性位点的局部原子和电子结构，并能识别和了解生物样品中的金属位点。本文介绍了一种能够承受第四代同步加速器强烈硬X射线束和恶劣化学样品条件的微流控装置。该装置在铁和溴的K边缘以及铅的L边缘进行了评估，采用透射和荧光模式检测，并且在低至0.001 M的广泛样品浓度范围内进行了评估。该装置由硅和玻璃制成，在将玻璃晶圆阳极键合到完整装置之前，在硅晶圆中通过等离子体蚀刻定义微通道。该装置由精心设计的印刷芯片支架支撑，使微流控装置便于携带且易于操作。芯片支架在将精密的微流控装置安装到光束线平台上起着关键作用。测试验证了该装置足够坚固，能够容纳并流过强酸性和有毒样品。尽管用强X射线束聚焦数小时，也未观察到该装置有明显的辐射损伤。所采集的X射线光谱质量与标准方法相当；因此，我们展示了一种使用同步加速器XAS分析液体样品的坚固微流控装置。
