Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, USA.
University of North Carolina at Chapel Hill College of Arts and Sciences, Chapel Hill, North Carolina, USA.
Astrobiology. 2022 Sep;22(9):1116-1128. doi: 10.1089/ast.2021.0182. Epub 2022 Aug 17.
Increasing interest in the detection of biogenic signatures, such as amino acids, on icy moons and bodies within our solar system has led to the development of compact instruments. Given the expected dilute biosignatures and high salinities of these extreme environments, purification of icy samples before analysis enables increased detection sensitivity. Herein, we outline a novel compact cation exchange method to desalinate proteinogenic amino acids in solution, independent of the type and concentration of salts in the sample. Using a modular microfluidic device, initial experiments explored operational limits of binding capacity with phenylalanine and three model cations, Na, Mg, and Ca. Phenylalanine recovery (94-17%) with reduced conductivity (30-200 times) was seen at high salt-to-amino-acid ratios between 25:1 and 500:1. Later experiments tested competition between mixtures of 17 amino acids and other chemistries present in a terrestrial ocean sample. Recoveries ranged from 11% to 85% depending on side chain chemistry and cation competition, with concentration shown for select high affinity amino acids. This work outlines a nondestructive amino acid purification device capable of coupling to multiple downstream analytical techniques for improved characterization of icy samples at remote ocean worlds.
对太阳系内冰冷卫星和天体中生物特征（如氨基酸）的检测兴趣日益浓厚，这推动了紧凑型仪器的发展。鉴于这些极端环境中预期存在的生物特征稀释度和高盐度，在分析之前对冰样进行纯化可以提高检测灵敏度。在此，我们概述了一种新颖的紧凑型阳离子交换方法，用于在不考虑样品中盐的类型和浓度的情况下对溶液中的蛋白氨基酸进行脱盐。使用模块化微流控装置，初步实验探索了与苯丙氨酸和三种模型阳离子（Na、Mg 和 Ca）结合容量的操作极限。在 25:1 至 500:1 的高盐与氨基酸比下，观察到苯丙氨酸的回收率（94-17%）和电导率降低（30-200 倍）。后来的实验测试了 17 种氨基酸混合物与陆地海洋样本中存在的其他化学物质之间的竞争。根据侧链化学和阳离子竞争，回收率在 11%至 85%之间变化，选择高亲和力氨基酸时可显示浓度。这项工作概述了一种非破坏性的氨基酸纯化设备，可与多种下游分析技术相结合，以改善对远程海洋世界中冰样的特征描述。
