Scientists have developed a new electrical technique that could help detect signs of life in space. The method identifies the handedness of amino acids at the level of single molecules.

The study was published in the journal Nature Communications. Researchers used single-molecule nanogap conductance to tell apart the two mirror-image forms of amino acids, a feat never achieved before at this scale.

This matters because life on Earth uses only left-handed amino acids. Finding the same imbalance on another world could be a strong hint of biology at work.

To test the method on real samples, the team analysed extracts from the Murchison meteorite in Australia and soil from the Atacama Desert in Chile. The technique performed as well as traditional methods in capturing the main features of the samples.

Senior author Masateru Taniguchi hopes the work leads to compact, electrically based instruments for future space missions. Such devices could sniff out the chemical fingerprints of life far more simply than today’s bulky lab equipment.