Tech

A small thermometer directly monitors the temperature change as the ions pass through the nanopores.

Schematic diagram showing the process of ion heat dissipation in nanopores (left). A nanoscale thermometer (right) embedded in one side of the nanopore to detect local temperature changes caused by voltage-driven ion transport. Credits: © 2022 M. Tsutsui et al. , Ion heat dissipation in solid pores.Science Advances

Scientists at the Institute of Scientific and Industrial Research (SANKEN), Osaka University, used thermocouples to measure the thermal effect of the ionic flow through the nanopores. They found that under most conditions, both current and heating power vary with the applied voltage, as predicted by Ohm’s law. This work could lead to more advanced nanoscale sensors.


Nanopores are small openings in the membrane, so only a single DNA strand or Virus particles An exciting new platform for building sensors that can be passed through. Often, a voltage is applied between both sides of the membrane to draw in the material to be analyzed. Nanopore.. At the same time, it is possible to transport charged ions in solution, but its effect on temperature has not been extensively studied. By directly measuring the thermal effects caused by these ions, nanopores can be made more practical as sensors.

Currently, a team of researchers at Osaka University have created a thermocouple made of gold and platinum nanowires with contact points measuring only 100 nm, which acts as a thermometer. It was used to measure the temperature immediately next to a nanopore cut into a 40 nm thick film suspended on a silicon wafer.

Joule heat occurs when: Electrical energy Will be converted to heat By the resistance of the wire. This effect occurs in toasters and electric stoves and can be thought of as inelastic scattering by electrons when they collide with the core of a wire.In the case of Nanopore, scientists have discovered it Thermal energy It dissipated in proportion to the momentum of the ion current according to the prediction of Ohm’s law. When studying 300 nm sized nanopores, researchers recorded the ion current of phosphate buffered saline as a function of applied voltage. “We have shown almost Ohm behavior under a wide range of experimental conditions,” says lead author Maku Tsutsui.

The smaller the nanopore, the less fluid from the cooling side and the more uniform the temperature, the more pronounced the heating effect. As a result, heating can cause non-negligible effects, and nanopores experience several degrees of temperature rise under standard operating conditions. “We look forward to the development of new nanopore sensors that not only identify viruses but also have the potential to deactivate viruses at the same time,” said senior author Tomoji Kawai. Researchers have suggested other situations where heating may be beneficial. For example, to prevent the nanopores from being clogged by the polymer, or to separate the strands of sequenced DNA.

The article “Ion heat dissipation in solid pores” Science Advances..


Initu extraction and detection of DNA using nanopores


For more information:
Makusu Tsutsui et al, Ion heat dissipation in solid pores, Science Advances (2022). DOI: 10.1126 / sciadv.abl7002.. www.science.org/doi/10.1126/sciadv.abl7002

Provided by
Osaka University

Quote: A small thermometer directly monitors the temperature change as the ions pass through the nanopore (2022, February 11). Obtained from https: //phys.org/news/2022-02-tiny-thermometer-temperature-ions-nanopore.html on February 11, 2022

This document is subject to copyright. No part may be reproduced without written permission, except for fair transactions for personal investigation or research purposes. Content is provided for informational purposes only.



A small thermometer directly monitors the temperature change as the ions pass through the nanopores.

Source link A small thermometer directly monitors the temperature change as the ions pass through the nanopores.

Show More

Related Articles

Back to top button