Gold Nanoparticle Coated Carbon Nanotube Ring with Enhanced Raman Scattering and Photothermal Conversion Property for Theranostic Applications

Abstract

We report a new type of carbon nanotube ring (CNTR) coated with gold nanoparticles (CNTR@AuNPs) using CNTR as a template and surface attached redox-active polymer as a reducing agent. This nanostructure of CNTR bundle embedded in the gap of closely attached AuNPs can play multiple roles as a Raman probe to detect cancer cells and a photoacoustic (PA) contrast agent for imaging-guided cancer therapy. The CNTR@AuNP exhibits substantially higher Raman and optical signals than CNTR coated with a complete Au shell (CNTR@ AuNS) and straight CNT@AuNP. The extinction intensity of CNTR@AuNP is about 120-fold higher than that of CNTR at 808 nm, and the surface enhanced Raman scattering (SERS) signal of CNTR@AuNP is about 110 times stronger than that of CNTR, presumably due to the combined effects of enhanced coupling between the embedded CNTR and the plasmon mode of the closely attached AuNPs, and the strong electromagnetic field in the cavity of the AuNP shell originated from the intercoupling of AuNPs. The greatly enhanced PA signal and photothermal conversion property of CNTR@AuNP were successfully employed for imaging and imaging-guided cancer therapy in two tumor xenograft models. Experimental observations were further supported by numerical simulations and perturbation theory analysis.

Self-Assembly of Semiconducting-Plasmonic Gold Nanoparticles with Enhanced Optical Property for Photoacoustic Imaging and Photothermal Therapy

“…The enhancement of PA signal of the hybrid vesicle was confirmed by simulating the optical spectra and near-field distribution with the discrete dipole approximation (DDA) using the DDSCAT 7.3 program. In vivo experimental results demonstrated that the hybrid vesicle is an excellent candidate as both PA imaging probe and photothermal agent for cancer theranostics 30, 38…”

Highly Efficient Solar‐Driven Photothermal Performance in Au‐Carbon Core‐Shell Nanospheres

“…The photothermal effects (PTE) have already shown a variety of practical applications, such as photo‐therapy, biomedical imaging, catalysis, controlled‐release systems, photothermal melting of DNA, and solar steam generation . Tremendous efforts have been dedicated to photothermal materials stimulated by near infrared (NIR) laser . However, until now the PTE of the broadband absorber are still low .…”

Synergized Multimodal Therapy for Safe and Effective Reversal of Cancer Multidrug Resistance Based on Low‐Level Photothermal and Photodynamic Effects

“…Given gold nanodots' plasmonic resonance feature, Au nanodots on HCNs' surface promoted the absorption of light from NIR wavelength (750–1200 nm) (Figure E). NIR (808 nm; the wavelength of NIR laser used for all experiments) irradiation increased AuHCNs' temperature in a dose‐dependent manner, and was always approximately twofold higher than HCNs (Figure F; Figures S7 and S8, Supporting Information).…”