Experimental and theoretical investigation of the photothermal effect in gold nanorods

Abstract

In this work, gold nanorods (GNRs) were synthesized using a seed-mediated route and their photothermal properties were investigated experimentally as well as theoretically. The structure and optical properties of the samples were also characterized by their X-ray diffraction (XRD) pattern, and Ultraviolet-Visible (UV-Vis) spectroscopy, High Resolution Transmission Electron Microscopy (HRTEM) and Energy Dispersive X-ray (EDX) images. The HRTEM images confirmed that the synthesized GNRs possess a length of about 33 ± 0.3 nm and a diameter of 11.5 ± 0.2 nm; therefore the obtained GNRs have an aspect ratio of about 3 having a plasmon resonance peak at 760 nm wavelength. Since the produced photothermal heat of the synthesized GNRs by near-infrared (NIR) laser irradiation can be applied in photothermal therapy, a photothermal experiment was performed for GNR suspensions in water as well as MoS₂ aqueous solution. The photothermal results confirm that the temperature of the MoS₂-GNR suspension increases with GNR concentration increasing after 10 min laser irradiation. Then numerical simulation was used to compare its thermal properties with the results of the photothermal experiment for a GNR sample. Finally, the outcome indicated that GNRs and MoS₂-GNR suspension can be used as two good candidates in photothermal therapy and also there is a fairly good agreement between experimental and theoretical results.