Synergistic Effect in Hybrid Plasmonic Conjugates for Photothermal Applications.

Photothermal conversion efficiency (η) plays a crucial role in selecting suitable gold nanoparticles for photothermal therapeutic applications. The photothermal efficiency depends on the material used for the nanoparticles as well as their various parameters, such as size and shape. By maximizing the light-to-heat conversion efficiency (η), one can reduce the concentration of nanoparticle drugs for photothermal cancer treatment and apply lower laser power to irradiate the tumor.

Absorption cross section of gold nanoparticles based on NIR laser heating and thermodynamic calculations.

We present a method for measuring the optical absorption cross section ([Formula: see text]) of gold nanoparticles (GNPs) based on optically heating the solution of GNPs with an 808 nm near-infrared (NIR) laser and measuring the temperature increase of the solution. We rely on the theoretical calculations based on the heat diffusion equations and experimental measurements based on the energy balance equations to measure the [Formula: see text] and the temperature distribution of single GNPs. Several morphologies, including gold nanospheres (GNSs), spherical gold nanoparticle conjugate (AuNPC), which are 20 nm GNSs surface-functionalized with an IR 808 dye, gold nanorods (GNRs), and gold nanourchins (GNUs), were studied.

Particle-substrate interactions in the laser deposition process.

We theoretically study particle-substrate interactions under laser irradiation. Van der Waals, electrostatic double layer and a laser induced dipole in the nanoparticle and an image dipole in the substrate were considered to be the major components of the total interaction potential. It was shown that laser-induced attractive potential energy between the particle and substrate reduces the potential barrier which increases the probability for metal nanoparticles to be deposited onto the substrate.