Researchers created a fully automated microchip electrophoresis analyzer combined that can detect organic biosignatures in soil and could one day find alien life.
Organic molecules are a major piece of evidence when trying to find life beyond Earth. Past Mars missions have relied on gas chromatography and mass spectrometry to separate and detect compounds on other planets. But there are limitations to this method, especially when organic acids in water, minerals or salts are in the sample.
A fully automated microchip electrophoresis analyzer could someday be deployed in the search for life on other worlds. Source: Analytical Chemistry
Microchip electrophoresis (ME)-based separations followed by laser-induced fluorescence (LIF) detection are the preferred methods when analyzing soil for biosignatures. Current instruments that use these methods are only partially automated, which wouldn’t work for interplanetary missions.
The team set out to create a portable, battery-powered ME-LIF instrument that could gather samples and perform labeling, separation and detection of organic molecules that are fully automated.
The new device consists of two microchips and a LIF detection system. The first microchip processes and labeling the liquid sample. The second microchip is the ME chip, which separates the compounds. After optimizing the device, the team tested it in a simulated Mars mission on a Chilean desert.
Then the analyzer was paired with a portable subcritical water extractor on a remotely deployed rover system. The rover drilled into the soil to collect and deliver a sample to the extractor. Water is added to the soil samples and heated to extract the compounds for analysis. The device detected the parts per billion levels of amino acids in the soil from three out of the four drilling locations. The device’s sensitivity had three orders of magnitude higher than the levels than the GC-MS-based methods reported.
The team says that more work is needed for instruments to be ready for space flight and extraterrestrial conditions.
A paper on this research was published in Analytical Chemistry.
