Scientists at Osaka University have built a nanotechnology tool that can tell left-handed amino acids from right-handed ones, one molecule at a time. The work was published in Nature Communications on October 5.

The device uses a nanogap — a gap just billionths of a metre wide — combined with AI to identify molecules. It achieved over 80 percent accuracy in distinguishing the two mirror forms.

Life on Earth uses mostly left-handed amino acids. Finding the same bias elsewhere would be a strong hint of biology, making chirality a key biosignature.

The team tested the tool on the Murchison meteorite, which fell in Australia in 1969, and on soil from Chile’s Atacama Desert. Both contain amino acids of debated origin.

The researchers say the technology could one day fly on compact space instruments, hunting for signs of life on Mars, Europa and beyond.

The Murchison meteorite is famous for containing organic compounds from the early solar system. Scientists have debated for decades whether its amino acids came from space or Earth contamination.

Single-molecule tools like this could settle such debates. By reading molecules one by one, researchers can spot patterns that bulk analysis misses.