Light-Triggered Covalent Coupling of Gold Nanoparticles for Photothermal Cancer Therapy.

Manipulating the cross-coupling of gold nanoparticles (AuNPs) to maximize the photothermal effect is a promising strategy for cancer therapy. Here, by taking advantage of the well-known tetrazole/alkene photoclick chemistry, we have demonstrated for the first time that small AuNPs (23 nm) decorated with both 2,5-diphenyltetrazole and methacrylic acid on their surfaces can form covalently crosslinked aggregates upon laser irradiation (λ=405 nm). In vitro studies indicated that the light-triggered assembling shifted the surface plasmon resonance of AuNPs significantly to near-infrared (NIR) regions, which as a consequence effectively enhanced the efficacy of photothermal therapy for 4T1 breast cancer cells. We thus believe that this new light-triggered cross-coupling approach might offer a valuable tool for cancer treatment.