Scientists have created a tiny sensor capable of something truly extraordinary: it can “remember” the molecules it has previously encountered. Inspired by the way living organisms respond to their environments, this innovative technology could pave the way for smarter sensors used in medical diagnostics, biological research, and even future computing applications.
Published in ACS Nano, this research was conducted by scientists from the SANKEN research institute at the University of Osaka, along with their collaborators. Their device builds upon the concept of a nanopore—a minuscule opening already widely used to detect biological molecules like DNA and proteins.
A nanopore is an incredibly tiny hole, measuring just a few billionths of a meter across. When molecules pass through it, they cause subtle fluctuations in an electrical current, which can be measured to identify different substances. This method has become vital in DNA sequencing and medical testing. However, traditional nanopores are passive—they remain unchanged and simply record everything that passes through.
This new nanopore, however, functions very differently. Instead of staying static, it continuously alters its own structure during operation. When a constant electrical voltage is applied, chemical reactions inside the small opening repeatedly produce and dissolve microscopic mineral deposits. As a result, the nanopore opens and closes on its own, without any external control.
These ongoing structural shifts generate a constantly changing environment within the sensor. When molecules such as DNA building blocks or amino acids travel through the nanopore, they influence these internal chemical reactions. In turn, these reactions affect how the nanopore behaves in subsequent measurements. Essentially, each molecule leaves behind more than just an electrical signature—it impacts the nanopore’s future responses. This allows the sensor to retain a short-term memory of recent interactions, making its signals richer and more informative than those from traditional nanopores.
The researchers employed machine learning algorithms to analyze these complex electrical patterns. The system was able to successfully distinguish all four nucleotides— the building blocks of DNA—and also accurately analyze mixtures containing multiple different nucleotides. They went further by identifying seven different amino acids, the molecules that come together to form proteins. Notably, all these measurements were performed without actively controlling the nanopore during sensing, relying solely on its self-changing behavior.
This breakthrough introduces a new perspective on molecular sensors. Instead of merely detecting molecules passively, future nanopores could actively respond and adapt based on their experiences. Such technology could significantly enhance disease diagnosis, accelerate biological research, and simplify the analysis of complex molecular mixtures.
Additionally, this development may contribute to the rising field of iontronics—an emerging area that uses charged atoms, or ions, to process information instead of electrons. Although still in the experimental stage, the study demonstrates that tiny sensors can combine detection, memory, and signal processing within a single device. Empowering nanopores with the ability to remember previous interactions marks a major step toward creating a new generation of intelligent nanoscale sensors.