Tiny pores that can sense molecules are being transformed into autonomous chemical machines capable of generating signals, adapting to their surroundings and retaining a memory of what they have recently encountered. In a study published in ACS Nano, researchers at SANKEN, the University of Osaka, and collaborating institutions have developed a solid-state nanopore that does not simply detect molecules as they pass through. Instead, it continually remodels itself through chemical reactions, producing changing electrical signals that encode both the identity of incoming molecules and the pore’s recent history.
Nanopores are openings only a few billionths of a meter wide. When a voltage is applied across a membrane containing one of these openings, ions flow through the pore and create an electrical current. A molecule such as DNA, a protein or a small metabolite can temporarily obstruct that flow as it passes through, causing a measurable change in current. Conventional nanopore sensors generally rely on fixed pore structures and external electronics to interpret these changes. Their behavior is largely determined before sensing begins, meaning that the pore itself remains a passive component.
The new device operates according to a very different principle. Under a constant voltage, chemical reactions inside the nanopore cause tiny mineral deposits to form and dissolve repeatedly. As these deposits accumulate, the effective diameter of the pore decreases; when they dissolve, the opening expands again. This self-organized process makes the nanopore alternate autonomously between more open and more restricted states. Each transition changes the ionic current, generating bursts or spikes of electrical activity without the need for an external switch to control the pore.
This behavior gives the nanopore a form of built-in dynamical memory. Its electrical response at any particular moment depends not only on the molecule currently passing through, but also on the pore’s immediately preceding chemical and structural states. A molecule encountered moments earlier can therefore influence how the pore responds to the next one. Rather than producing an identical signal every time a particular molecule appears, the sensor generates state-dependent patterns in which spike amplitude, duration, frequency and timing all carry information.
The researchers found that nucleotides and amino acids interact with this continuously changing environment in distinctive ways. As these molecules move through the pore, they can influence ion transport and alter the chemical processes responsible for mineral deposition and dissolution. The result is a complex electrical signature that reflects both molecular properties and the nanopore’s evolving condition. This is technically significant because it turns the device from a static molecular filter into a chemically active system whose sensing process is intertwined with its own internal dynamics.
To interpret the signals, the team used machine-learning methods capable of analyzing patterns that would be difficult to classify with simple thresholds. The system successfully distinguished the four DNA nucleotides—adenine, thymine, cytosine and guanine—even though the nanopore was changing autonomously during measurement. The researchers also analyzed mixtures containing multiple nucleotides and extended the approach to seven different amino acids. In each case, the device generated information-rich electrical patterns that could be separated computationally without active control of the pore during sensing.
The combination of autonomous operation, chemical responsiveness and memory could address some of the limitations of conventional nanopore technologies. Fixed nanopores can be highly sensitive, but their performance often depends on carefully engineered geometries, stable operating conditions and sophisticated external instrumentation. A pore that actively adjusts its own structure may access a wider range of signal states and create additional layers of information. Because sensing, signal generation and short-term memory are integrated into the same nanoscale element, the architecture resembles an artificial chemical system more closely than a traditional electronic sensor.
The work also points toward iontronic devices, which process information through the movement of ions rather than electrons. Biological systems routinely combine sensing, memory and decision-making through chemical feedback networks, and the autonomous nanopore applies a related idea in an inorganic material. Such devices could eventually support molecular analysis in biomedical research, diagnostics and environmental monitoring, although further studies will be needed to establish their long-term stability, selectivity, reproducibility and performance in complex biological samples.
For the researchers, the most important shift is conceptual: a nanopore need not remain a passive hole through which molecules travel. By exploiting chemical feedback, it can become an active nanoscale machine that continuously modifies its own sensing landscape. The study, titled “Autonomous molecular sensing with a chemically stateful solid-state nanopore,” demonstrates how a single device can detect molecules, produce electrical activity and preserve a memory of recent events. That convergence could help drive the next generation of intelligent molecular sensors, in which materials do more than transmit information—they actively participate in creating and interpreting it.
Subject of Research: Not applicable
Article Title: Autonomous molecular sensing with a chemically stateful solid-state nanopore
News Publication Date: 30-Jul-2026
Web References: https://doi.org/10.1021/acsnano.6c08258
References: ACS Nano, DOI: 10.1021/acsnano.6c08258
Image Credits: Makusu Tsutsui
Keywords
Nanotechnology, nanopores, molecular sensing, nanomaterials, materials engineering, chemistry, biotechnology, electronics, artificial intelligence, biochemical engineering, biophysics, iontronics
