Center for Space and Habitability, University of Bern, Bern, Switzerland.
Space Research and Planetary Sciences, Physics Institute, University of Bern, Bern, Switzerland.
Sci Rep. 2020 Jun 15;10(1):9641. doi: 10.1038/s41598-020-66240-1.
For the last four decades space exploration missions have searched for molecular life on planetary surfaces beyond Earth. Often pyrolysis gas chromatography mass spectrometry has been used as payload on such space exploration missions. These instruments have relatively low detection sensitivity and their measurements are often undermined by the presence of chloride salts and minerals. Currently, ocean worlds in the outer Solar System, such as the icy moons Europa and Enceladus, represent potentially habitable environments and are therefore prime targets for the search for biosignatures. For future space exploration missions, novel measurement concepts, capable of detecting low concentrations of biomolecules with significantly improved sensitivity and specificity are required. Here we report on a novel analytical technique for the detection of extremely low concentrations of amino acids using ORIGIN, a compact and lightweight laser desorption ionization - mass spectrometer designed and developed for in situ space exploration missions. The identified unique mass fragmentation patterns of amino acids coupled to a multi-position laser scan, allows for a robust identification and quantification of amino acids. With a detection limit of a few fmol mm, and the possibility for sub-fmol detection sensitivity, this measurement technique excels current space exploration systems by three orders of magnitude. Moreover, our detection method is not affected by chemical alterations through surface minerals and/or salts, such as NaCl that is expected to be present at the percent level on ocean worlds. Our results demonstrate that ORIGIN is a promising instrument for the detection of signatures of life and ready for upcoming space missions, such as the Europa Lander.
在过去的四十年中,太空探索任务一直在行星表面上寻找地球以外的分子生命。通常,热解气相色谱-质谱联用仪被用作此类太空探索任务的有效载荷。这些仪器的检测灵敏度相对较低,其测量结果常常受到氯化物盐和矿物质的影响。目前,太阳系外的海洋世界,如冰冷的木卫二和土卫二,代表着潜在的宜居环境,因此是寻找生物特征的主要目标。对于未来的太空探索任务,需要新型的测量概念,这些概念能够以显著提高的灵敏度和特异性检测低浓度的生物分子。在这里,我们报告了一种使用 ORIGIN 检测极低浓度氨基酸的新型分析技术,ORIGIN 是一种专为原位太空探索任务而设计和开发的紧凑型、重量轻的激光解吸电离-质谱仪。与多位置激光扫描相结合的氨基酸独特质量碎片模式,允许对氨基酸进行稳健的识别和定量。该测量技术的检测限为几个 fmol/mm,并且有可能达到亚 fmol 检测灵敏度,其灵敏度比当前的太空探索系统高出三个数量级。此外,我们的检测方法不受表面矿物质和/或盐分(如预计在海洋世界中存在的 NaCl)的化学变化的影响。我们的结果表明,ORIGIN 是一种用于检测生命特征的有前途的仪器,并且已经为即将到来的太空任务做好了准备,例如 Europa 着陆器。