Electrospray sample injection for single-particle imaging with x-ray lasers

Abstract

The possibility of imaging single proteins constitutes an exciting challenge for x-ray lasers. Despite encouraging results on large particles, imaging small particles has proven to be difficult for two reasons: not quite high enough pulse intensity from currently available x-ray lasers and, as we demonstrate here, contamination of the aerosolized molecules by nonvolatile contaminants in the solution. The amount of contamination on the sample depends on the initial droplet size during aerosolization. Here, we show that, with our electrospray injector, we can decrease the size of aerosol droplets and demonstrate virtually contaminant-free sample delivery of organelles, small virions, and proteins. The results presented here, together with the increased performance of next-generation x-ray lasers, constitute an important stepping stone toward the ultimate goal of protein structure determination from imaging at room temperature and high temporal resolution.

The role of transient resonances for ultra-fast imaging of single sucrose nanoclusters

“…1. The sucrose clusters were generated by aerosolizing a sugar solution and focusing the resulting dried particles into the interaction region with an aerodynamic lens stack 35,48 . The XFEL delivered pulse energies ranging from 1 to 2 mJ depending on the photon energy.…”

Fabrication of Polymeric Microparticles by Electrospray: The Impact of Experimental Parameters

“…It is noteworthy that particles in the sub-micro range (0.1-1.0 µm) have also been designed through ES such as macrovesicles and micro sized proteins for therapeutic and imaging applications [67][68][69]. Despite that one may think that there is not much difference between micrometer and submicrometer particles apart from the small size difference, they actually display fairly different properties such as surface area to volume ratios, differences in their fabrication, interactions with cells, and therefore provide different responses to the dynamic and complex in vivo environment making sub-micron and nanoparticles often more suitable for different applications.…”

Coherent X-ray imaging technology

“…使用XFELs照射样本时, 有多种样本制备方式, 如 液体微射流、挤出射流、气溶胶喷射器、光栅扫描阵 列和安装在测角仪上的冷冻环上的大晶体. 其中背景 噪声最低的为Bielecki等人 [38] , 在真空中使用气动虚拟 喷嘴(gas-dynamic virtual nozzle, GDVN) [39] 和电喷雾 (electrospray, ES)雾化样品溶液来产生液滴气溶胶 束 [40] , 经空气动力学透镜聚焦成窄光束, 再引导到 XFEL焦点中以对单个气溶胶粒子衍射成像(图3D-a). .…”

“…(b) 通过RSM(顶 部)和XFEL衍射(底部)确定的ES(绿色)和GDVN(蓝色)气溶胶的初始液滴的尺寸分布. 图片来源: 参考文献 [38] [19]. B: (a) Experimental geometry used in the proposed simulated experiment.…”