Investigating the Performance of Near‐Infrared Light Responsive Monometallic Gold and Bimetallic Gold‐Palladium Nanorattles towards Plasmonic Photothermal Therapy

Abstract

AbstractThe effect of different sizes and shapes of nanomaterials on its extinction spectrum is well studied and accordingly researchers have designed various nanostructures having absorbance in the near infrared (NIR) region for plasmonic photothermal therapy (PPTT) applications. However, the comparative study between the NIR active nanomaterials having different elemental composition for PPTT applications is not well explored. Herein, we investigate the photothermal activity of two different NIR active nanorattles viz. gold nanorattle (Au NRT) and bimetallic gold‐palladium nanorattle (Au−Pd NRT) having identical morphology but different elemental composition. The prepared nanorattles were PEGylated to render biocompatibility and identical surface functionalities. The aqueous solution of both the NRTs displayed a significant rise in temperature upon NIR irradiation which was not compromised on repeated exposure to light. The PPTT applicability of both the nanorattles were evaluated which suggested that the bimetallic Au−Pd NRT have better photothermal conversion efficiency of 35.4 % and better photothermal killing ability towards breast cancer cell line (SK‐BR‐3) compared to that of monometallic Au NRT having photothermal conversion efficiency of only 19.8 %. Thus, the present study indicates that NIR active nanostructures based on palladium acts as a better phototransducing agent than that of gold with similar morphology.