"Nanogate Breakthrough for Molecule Control"

A recent breakthrough reported by researchers at Osaka University describes the development of a nanogate that can dynamically control the passage of molecules through a minute pore by applying an electric voltage. This innovative technology demonstrates various functionalities that depend on the materials present in the solution on either side of the nanogate and the applied voltage, making it promising for diverse applications, including sensing and controlled chemical reactions.

The Technology Behind the Nanogate

The design of the nanogate features a single tiny pore created in a silicon nitride membrane situated within a flow cell on a chip. This setup allows for solutions to be introduced on both sides of the membrane. By applying voltage through electrodes integrated into the chip, researchers were able to monitor the resulting ionic current, which offers insights into the ion transport through the pore. This ionic current is sensitive to the composition of ions in the solutions on either side, permitting precise control over the ion flow, leading to either precipitation or dissolution of metal compounds within the pore.

"Precipitates grew and closed the pore under forward bias, decreasing ionic current," says Makusu Tsutsui, the lead author of the study. "Reversing the voltage polarity allowed the precipitates to dissolve, reopening the pore."

Behavioral Analysis of the Nanogate

The functionality of the nanogate hinges upon two primary actions: the precipitation that narrows or closes the pore and the dissolution that reopens it.

• Precipitation: This process occurs under specific voltage conditions, leading to a decreased ionic current.
• Dissolution: Inversion of voltage polarity triggers the dissolution of the precipitate, resulting in the restoration of the pore's diameter and the ionic current.

Innovation in Ion Transport

Under precise conditions, the characteristics of the pore can be modulated so that precipitate formation leads to the highest recorded rectification ratio for any nanofluidic device, meaning that ions can preferentially flow in one direction. Moreover, the system exhibited memristor properties, implying a memory effect based on the relationship between applied current and voltage. The sequential precipitation and dissolution phenomena within the pore contribute to this memristive behavior.

Applications in Biomolecule Detection

The researchers successfully demonstrated that the in-pore reactions could be tailored for biomolecule detection, particularly using DNA as a model. The system generated distinctive output signals correlating to the movement of single DNA molecules through the pore, showcasing its potential in:

• Biomolecule detection: The ability to control ion flow and monitor biomolecules is significant for diagnostics and sensing applications.
• Neuromorphic computing: The properties of the nanogate can be leveraged for developments in neuromorphic systems that mimic neural structures.
• Controlled chemical reactions: Tailoring the pore for specific analytes immediately before conducting measurements allows for targeted chemical synthesis.

Conclusions and Future Directions

The advancement represented by this nanogate offers a versatile platform for electrochemical devices. By employing a single controlled pore, the device can be adjusted for various applications, significantly extending its utility in fields such as:

This research provides a foundation for future advancements in nanotechnology and its applications across multiple scientific disciplines.

Reference

Transmembrane voltage-gated nanopores controlled by electrically tunable in-pore chemistry. Nature Communications (2025). Retrieved February 5, 2025 from Lifespan.io

As ongoing research continues to refine these technological applications, the potential for profound impacts across scientific and technological domains remains significant.