The surface plasmon resonance of gold nanorods (GNRs) is easily excited via near infrared (NIR) laser irradiation, which generates heat rapidly throughout the photothermal conversion phenomenon. The temperature increase is due to the electronic motion on the surface of the GNRs that causes irreversible damage to the targeted area.

The team synthesized GNRs using a seed mediated growth method and a single GNR cluster was fabricated using photo-lithography. In the study, the researchers demonstrated that the laser-induced heating together with the thermal interaction in the GNRs resulted in considerable spatial and temporal rises in temperature in and around the GNR cluster.

As shown in the images, the GNR cluster significantly affected not only bacterial cell membranes, but also disrupted multi-layered biofilm structures.

Photothermal treatment using the GNR clusters and NIR irradiation may be highly desirable for GNR-based automatic disinfecting technology that could be applied to various devices, such as touchscreens.

More information can be found in the journal Nanotechnology.