Construction of aptamers-modified plasmonic GO/urchin-like Au nanoparticles with enhanced photothermal performance and their efficient capture and elimination of Staphylococcus aureus

Here, aptamers-modified graphene oxide/urchin-like Au nanoparticles (Apt-GUANPs) were developed for efficient capture and photothermal therapy (PTT) of Staphylococcus aureus ( S. aureus) . Specifically, anisotropic UANPs were first prepared, and the excellent photothermal property was related to the localized surface plasmon resonance (LSPR) in the near infrared (NIR) region caused by sharp branching. Then GO, which was used to enhance the photothermal effect, was added and assembled into GUANPs by electrostatic action. Infrared images showed that GUANPs exhibited a stronger photothermal effect than UANPs. Under the irradiation of 808 nm laser, the photothermal conversion efficiency (η) of GUANPs was as high as 40.5 %, which was attributed to the enhanced optical response of GUANPs at 808 nm and the strong plasmonic coupling effect between tightly packed UANPs loaded on GO surfaces. Aptamers were modified on the surfaces of GUANPs for specific capture of S. aureus , with the capture efficiency of up to 72 %. Utilizing the specific capture ability of aptamers and the excellent photothermal property of GUANPs, Apt-GUANPs exhibited the strong photothermal killing ability against S. aureus . Therefore, Apt-GUANPs will be a promising and efficient photothermal agent, and will have a great application prospect in the treatment of bacterial infections in the future.