This method promises to be useful for future biomedical applications.
Scientists developed a method involving terahertz radiation for monitoring temperature changes when light. This technology works through particles that absorb light and convert it into localized heat sources, this innovation could be used in photothermal therapy, one of the new types of cancer treatment that involves focusing infrared laser light on nanoparticles near the treatment area.
Localized heating in these systems should be carefully monitored as the living tissue is delicate. There is a possibility of severe burns and tissue damage if unwanted heating is applied to the wrong site. The ability to control temperature increases is crucial in the development of this technology. Several approaches have been attempted, but all have drawbacks of various types, including the need to insert probes or inject additional materials.
In December 2019, reports on the development of this method to measure temperatures in this type of system, using terahertz radiation, were published in APL Photonic. To carry out this study, suspensions of gold nanobars of various sizes, placed in small buckets of water, were used. These were illuminated by a laser focused on a specific point in the bucket.
“We are able to map out the temperature distribution by scanning the cuvette with terahertz radiation, producing a thermal image,” said co-author Junliang Dong.
"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.