An emerging technology involving tiny particles that absorb light and turn it into localized heat sources shows great promise in several fields, including medicine. For example, photothermal therapy, a new type of cancer treatment, involves aiming infrared laser light onto nanoparticles near the treatment site.
Localized heating in these systems must be carefully controlled since living tissue is delicate. Serious burns and tissue damage can result if unwanted heating occurs in the wrong place. The ability to monitor temperature increases is crucial in developing this technology. Several approaches have been tried, but all of them have drawbacks of various kinds, including the need to insert probes or inject additional materials.
In this week’s issue of APL Photonics, from AIP Publishing, scientists report the development of a new method to measure temperatures in these systems using a form of light known as terahertz radiation. The study involved suspensions of gold nanorods of various sizes in water in small cuvettes, which were illuminated by a laser focused on a small spot within the cuvette.
The tiny gold rods absorbed the laser light and converted it to heat that spread through the water by convection. “We are able to map out the temperature distribution by scanning the cuvette with terahertz radiation, producing a thermal image,” co-author Junliang Dong said.
The study also looked at the way the temperature varied over time. “Using a mathematical model, we are able to calculate the efficiency by which the gold nanorod suspensions converted infrared light to heat,” said co-author Holger Breitenborn of Institut national de la recherche scientifique.
The smallest gold particles, which had a diameter of 10 nanometers, converted laser light to heat with the highest efficiency, approximately 90%. This value is similar to previous reports for these gold particles, indicating the measurements using terahertz radiation were accurate.
Although the smaller gold rods had the highest light-to-heat conversion efficiency, the largest rods — those with a diameter of 50 nanometers — displayed the largest molar heating rate. This quantity has been recently introduced to help evaluate the use of nanoparticles in biomedical settings.
“By combining measurements of temperature transients in time and thermal images in space at terahertz frequencies, we have developed a noncontact and noninvasive technique for characterizing these nanoparticles,” co-author Roberto Morandotti said. This work offers an appealing alternative to invasive methods and holds promise for biomedical applications.
Learn more: Turning Light Energy into Heat to Fight Disease
Go deeper with Bing News on:
- How to Combine Imaging and Therapy in Nanoparticles to Combat Canceron February 24, 2021 at 4:00 pm
Researchers from Imperial College London and the National Center for Scientific Research (CNRS) in Paris have designed and developed hybrid gold-silica nanoparticles, which could result in a genuine ...
- Photosynthetic bacteria-based cancer optotheranosticson February 15, 2021 at 3:59 pm
Active anticancer efficacy and powerful multi-functions such as NIR-I-to-NIR-II fluorescence, photothermal conversion, reactive oxygen species generation, and contrasty photoacoustic effect ...
- Gold Nanoparticles Help in Fighting Skin Canceron February 4, 2021 at 4:00 pm
University of Texas scientists have created a technique that utilizes gold nanoparticles to increase the efficiency of photothermal ablation when treating melanoma. During photothermal ablation ...
- Mechanical penetration of β-lactam–resistant Gram-negative bacteria by programmable nanowireson February 2, 2021 at 4:00 pm
However, as a result of the intensive use of β-lactam antibiotics in human therapy and animal agriculture ... 6), metal oxide nanoparticles (ZnO and TiO 2) (7, 8), photothermal agents (9), and ...
- Eradication of tumor growth by delivering novel photothermal selenium-coated tellurium nanoheterojunctionson February 2, 2021 at 4:00 pm
These authors contributed equally to this work. See allHide authors and affiliations Two-dimensional nanomaterial-based photothermal therapy (PTT) is currently under intensive investigation as a ...
Go deeper with Google Headlines on:
Go deeper with Bing News on:
- Frequency-domain terahertz systems poised for miniaturizationon February 24, 2021 at 7:01 am
A new fiber-based system enables fast measurements with sub-micron precision; the next step will be integration of all components towards chip-size.
- Global Terahertz Radiation System Market 2020 Sales Revenue, Key Players Analysis, Development Status, Opportunity Assessment and Forecast by 2025on February 23, 2021 at 8:46 pm
MarketsandResearch.biz has announced the addition of a new report entitled Global Terahertz Radiation System Market 2020 by Manufacturers, Type and Application, Forecast to 2025 that provides a ...
- T-ray imaging gets under the skinon February 17, 2021 at 2:00 am
This requires the use of terahertz (THz) radiation or T-rays, which form a little-exploited part of the electromagnetic spectrum. With frequencies of 0.3-3.0THz and wavelengths of 100 micrometres to ...
- Easy Screening for Skin Canceron February 12, 2021 at 8:07 am
Scientists from the Faculty of Engineering at CUHK and the University of Warwick have developed a novel method for analysing skin structure using a type of radiation known as Terahertz radiation ...
- Apple could be working on terahertz radiation sensor for non-invasive Glucose Monitoringon February 12, 2021 at 7:21 am
of the previous ‘Gas Sensor’ design. Consequently, its new patent talks about using terahertz(THz) electromagnetic radiation(EMR) on previous spectroscopy methods. A transmitter of the ...