Scientists use AI and nanotechnology to detect signs of life in space.
Researchers report an electrical method that uses quantum tunneling currents to distinguish L- and D-amino acids one molecule at a time, and they tested it on meteorite and desert extracts.
A research team has described a way to tell mirror-image forms of amino acids apart by measuring quantum tunneling currents through single molecules, according to a research paper. The method works without optical measurements and without chiral recognition molecules.
The work targets a long-standing idea in astrobiology. Life on Earth uses L-amino acids and D-sugars, while processes without life produce both mirror-image forms (enantiomers) in equal amounts. An excess of one form among biologically relevant molecules has therefore been proposed as a possible biosignature for life beyond Earth. The authors note that robust electrical methods for measuring L/D ratios at low concentrations, particularly in chemically complex samples, have been limited.
In their tests, the approach distinguished individual enantiomers with over 80% accuracy. In a blind test of 39 amino acids, it identified both the molecule and its chirality with more than 50% accuracy, which the authors say is well above random chance. Mixtures of four amino acids with different chiral compositions were quantified with more than 66% accuracy.
The team also analyzed extracts from the Murchison meteorite and the Atacama Desert using a targeted panel of 11 amino acids. A confidence-based filter separated high-confidence assignments from low-confidence events. The resulting compositions captured the major features seen with liquid chromatography mass spectrometry (LC-MS), though the authors say the results also showed the effects of background and low-abundance signals.
The authors describe the work as a targeted single-molecule electrical approach to chiral amino acid analysis. They present it as a foundation for future applications to chemically complex samples, including those relevant to astrobiological research.
Note: The headline says scientists detect signs of life in space and mentions AI. The page describes a lab method tested on meteorite and desert extracts, presented as a foundation for future astrobiology work, and does not mention AI.
At a Glance
- Individual L- and D-amino acid enantiomers were distinguished with over 80% accuracy using quantum tunneling currents.
- A blind test of 39 amino acids identified molecular identity and chirality with more than 50% accuracy.
- Four-amino-acid mixtures with different chiral compositions were quantified with more than 66% accuracy.
- Murchison meteorite and Atacama Desert extracts were analyzed using a targeted panel of 11 amino acids.
Sources
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