In the search for answers to one of the greatest questions about life in the cosmos—whether Earth is alone—scientists may soon have a formidable new tool to help spot any potential signs of alien biology on distant worlds.
A team at the University of Osaka has developed a new electrical sensing method of distinguishing between mirror-image forms and amino acids, one of the most significant potential biosignatures that could indicate the presence of life.
By combining the new technique with nanotechnology and artificial intelligence, the researchers say their approach could pave the way toward developing compact instruments that could advance the search for evidence of life on alien worlds.
The Search for Alien Biosignatures
The team’s new technique focuses on the property known as chirality, a phenomenon where a form or structure and its mirror image aren’t identical and thereby able to be superimposed.
In the case of amino acids, these protein “building blocks” can occur in two mirror-image forms scientists call L- and D-forms. Despite sharing the same chemical formula, life on Earth seems to prefer L-amino acids, while sugars generally occur in the D-form variant.
Nonbiological chemical and physical processes, by contrast, tend to produce roughly equal quantities of both of these, and a large amount of one over the other can signal the presence of biological activity.
Going Beyond the Gap
In the past, determining the ratio for this process has relied on the analysis of large volumes of molecules.
Now, the Osaka research team says their new method can put electricity to work in examining individual molecules as they travel through a microscopic gap between a pair of gold nanowires. As this occurs on a molecule-for-molecule basis, a tiny tunneling current is generated, each of which possesses its own characteristic waveform.
By using artificial intelligence to quickly analyze those signals, the research team says they were able to successfully distinguish between L- and D-amino acids with an accuracy of greater than 80% during experiments.
“By combining our nanogap tunneling technique with artificial intelligence, we were able to distinguish between the L- and D-forms of amino acids with over 80% accuracy,” said lead author Takahito Oshiro in a statement.
“This is the first discrimination of amino acid chirality at the single-molecule level and constitutes a fundamental advance in chemical sensing,” Oshiro added.
A Promising Advancement for Astrobiology
Employing the technique under conditions that might occur on distant worlds, where truly alien life forms may be present, might introduce a few conditions unlike those encountered with earthly materials. To overcome this, the researchers tested material derived from samples of Australia’s Murchison meteorite and soil collected from Chile’s Atacama Desert.
Senior author Masateru Taniguchi said that during tests with both materials, the team’s electrical method worked comparably well to existing methods that analyze larger numbers of molecules, with both techniques successfully capturing the major features of amino acid composition in the samples.
In the future, the team anticipates the technique they have developed could be used to incorporate tiny, electrical instruments that may play a significant role in advancing astrobiology missions. Such devices, they say, could give scientists a new way to search for one of life’s molecular fingerprints, and may ultimately help answer the longstanding question of whether we are indeed alone in the cosmos.
The team’s findings were featured in the recent study, “Chiral discrimination of amino acids in meteorite and desert soil extracts via single-molecule nanogap conductance,” which appeared in Nature Communications on October 5, 2026.
Micah Hanks is the Editor-in-Chief and Co-Founder of The Debrief. A longtime reporter on science, defense, and technology with a focus on space and astronomy, he can be reached at micah@thedebrief.org. Follow him on X @MicahHanks, and at micahhanks.com.