Smart sensor identifies present molecules by remembering the past
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Most sensors are designed to do only one thing: detect what passes through them. But what if a sensor could do more? To create a new generation of technology, researchers have looked to living systems for inspiration. If a sensor could detect molecules, could it also remember previous interactions and selectively respond to them?
Researchers have developed a device that does exactly that on a tiny scale, laying the groundwork for a new generation of smart molecular sensors.
In an article recently published in ACS Nano, researchers from SANKEN at the University of Osaka and collaborating institutions created an autonomous solid-state nanopore that can sense molecules, generate electrical signals and retain memories of recent events without external control. Unlike conventional nanopores, which act as passive channels, the new device continuously changes its own structure through chemical reactions, creating a dynamic sensing environment that responds to molecules passing through it.
A pore that reshapes itself
Nanopores are tiny holes only a few billionths of a meter wide, used to detect DNA, proteins and other biological molecules. They achieve this by measuring changes in electrical current as molecules pass through them. Most nanopores, however, act as fixed openings whose sensing behavior is determined by external electronics.
"Our nanopore works differently," says lead author Makusu Tsutsui. "Under a constant voltage supply, chemical reactions inside the pore repeatedly build up and dissolve tiny mineral deposits. This continual cycle causes the nanopore to repeatedly open and close on its own, producing bursts of electrical signals without any external switching."
These constantly changing openings also create a unique environment. As nucleotides and amino acids pass through the pores, they influence the ongoing chemical reactions and alter how the nanopore evolves over time.
"Different molecules change the size, duration and timing of the electrical spikes in distinctive ways, effectively leaving behind unique electrical signatures," explains Tomoji Kawai, senior author. "As each signal also depends on the nanopore's recent memory, the device behaves as a remembering, chemically active sensor."
Distinctive signals from molecular memory
The team then used machine learning to analyze these state-dependent signatures and successfully distinguished all four DNA nucleotides. They accurately measured mixtures containing multiple nucleotides and extended the approach to identify seven different amino acids, all without actively controlling the nanopore during sensing.
"This represents a shift in how nanopores are designed," Tsutsui says. "Instead of serving as passive channels that simply allow molecules to pass through, nanopores can actively respond to their chemical environment, giving them capabilities that go far beyond conventional sensing."
Such multifunctional nanopores could improve molecular analysis for biomedical research and diagnostics or contribute to emerging iontronic technologies that process information using ions instead of electrons. By integrating sensing capabilities, memory and signal generation into a single autonomous device, this work opens the door to a new generation of intelligent nanoscale systems.
Publication details
Autonomous molecular sensing with a chemically stateful solid-state nanopore, ACS Nano (2026). DOI: 10.1021/acsnano.6c08258. pubs.acs.org/ancac3/article/do … ano.6c08258/5228080/
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Citation: Smart sensor identifies present molecules by remembering the past (2026, August 2) retrieved 2 August 2026 from https://phys.org/news/2026-07-smart-sensor-molecules.html
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