Bacterial biofilm elimination using gold nanorod localised surface plasmon resonance generated heat

Antimicrobial resistance is an increasing global health concern and the world is facing a major challenge to develop novel ways of replacing antibiotics. Gold nanorods exhibit localised surface plasmon resonance upon optical irradiation. During relaxation, absorbed energy is dissipated as heat, which has been utilized to kill bacteria. In this study, 10×45nm gold nanorods were attached to glass surfaces using silanisation. Then biofilms were cultured on the surfaces and studied using microscopy. On average, 71% of the early biofilm bacteria were eliminated after 5min of near infrared radiation (LED emission peak at 850nm) of the gold nanorod coated surfaces, showing the potential of this novel antibiofilm technique. Most notably, the best individual result showed 97% biofilm elimination. This study demonstrates that nanoplasmonic generated heat offers a novel way of eliminating bacterial biofilms. In future applications, this method may be used to eliminate bacterial contamination during implant surgery.