Thermal Effect during Laser-Induced Plasmonic Heating of Polyelectrolyte-Coated Gold Nanorods in Well Plates

We examined the generation and transfer of heat when laser irradiation is applied to water containing a suspension of gold nanorods coated with different polyelectrolytes. The ubiquitous well plate was used as the geometry for these studies. The predictions of a finite element model were compared to experimental measurements. It is found that relatively high fluences must be applied in order to generate biologically relevant changes in temperature. This is due to the significant lateral heat transfer from the sides of the well, which strongly limits the temperature that can be achieved. A 650 mW continuous-wave (CW) laser, with a wavelength that is similar to the longitudinal plasmon resonance peak of the gold nanorods, can deliver heat with an overall efficiency of up to 3%. This is double the efficiency achievable without the nanorods. An increase in temperature of up to 15 degrees C can be achieved, which is suitable for the induction of cell death by hyperthermia. The nature of the polymer coating on the surface of the gold nanorods is found to have a small effect.

Automated summary

In this study, the generation and transfer of heat when laser irradiation is applied to water containing gold nanorods coated with different polyelectrolytes were investigated. Experimental measurements were compared to a finite element model. It was observed that high fluences are required to produce biologically relevant temperature changes due to significant lateral heat transfer from the well sides. A 650 mW continuous-wave laser with a wavelength similar to the gold nanorods' longitudinal plasmon resonance peak can deliver heat with an overall efficiency of up to 3%, which is double the efficiency without the nanorods. An increase in temperature of up to 15 degrees C, suitable for inducing cell death by hyperthermia, can be achieved. The nature of the polymer coating on the gold nanorods has only a small effect.