Electrically Controlled Nanogates: Tailoring Molecular Transport
Researchers at Osaka university have developed a groundbreaking nanotechnology tool: a tiny, electrically controlled gate capable of precisely regulating the movement of molecules.
Imagine a gate, but instead of controlling the flow of livestock, it manages the passage of individual molecules. This nanogate, developed by scientists at Osaka university’s SANKEN institute, holds immense potential for various applications, ranging from sensing and chemical reactions to neuromorphic computing.
A Nanometer-Scale Gatekeeper
This innovative device consists of a single pore etched into a silicon nitride membrane. This membrane acts as a barrier separating two fluid chambers, allowing researchers to introduce different solutions on either side. By applying an electrical voltage across the membrane, the researchers can precisely control the flow of ions through the pore, effectively opening and closing the nanogate.
“precipitates grew and closed the pore under negative voltage, decreasing ionic current,” explains Makusu Tsutsui, lead author of the study. “inverting the voltage polarity caused the precipitates to dissolve, reopening the pore.”
Tailoring Transport for Specific Applications
The nanogate’s versatility lies in its ability to respond differently depending on the materials present in the solutions.
Under specific conditions, the formation of precipitates within the pore resulted in the highest rectification ratio achieved to date for a nanofluidic device. This means ions are preferentially directed in one direction, opening doors for applications like molecular sieving and selective ion transport.
Furthermore, the nanogate exhibits a memory effect, known as memristive behavior. This arises from the sequential precipitation and dissolution of materials within the pore, allowing the device to store and recall details based on previous electrical stimuli.
Sensing and Beyond
The nanogate’s potential extends to biomolecule detection. Researchers demonstrated this by using DNA molecules.Distinct electrical signals were generated as individual DNA strands passed through the pore, showcasing its potential for highly sensitive genetic analysis.
“The ability to finely control pore size using applied voltage should allow pores to be tailored for specific analytes immediately before conducting measurements,” explains senior author Tomoji Kawai. “We also anticipate that our approach can be used to develop reaction systems to access new chemical compounds.”
looking Ahead: A Versatile Tool for Nanotechnology
This electrically controlled nanogate represents a significant advancement in nanotechnology. Its ability to precisely manipulate molecular transport opens exciting possibilities for:
Sensing: Detecting specific molecules, including biomolecules, with high sensitivity.
Chemical Reactions: Controlling chemical reactions at the nanoscale, enabling the synthesis of novel compounds.
* Neuromorphic Computing: Developing artificial neural networks inspired by the brain, perhaps leading to more efficient and powerful computing.
As research progresses, this versatile nanotechnology tool promises to revolutionize various fields, paving the way for groundbreaking discoveries and innovations.
