Plasmonic Bi nanoparticles encapsulated by N-Carbon for dual-imaging and photothermal/photodynamic/chemo-therapy

Abstract

In this work, the plasmonic Bi@N-Carbon@PEG-DOX nanocomposites were constructed to integrate the imaging and synergistic therapy in one nanoplatform. Here, Bi nanoparticles were encapsulated into the N-doped carbon nanomaterials via a simple solvothermal method. The accumulated adjacent semimetal Bi nanoparticles in Bi@N‑carbon enhanced the local surface plasmon resonance (LSPR) to make the great NIR harvest and high photothermal converting efficiency (52.3%, Bi@C-2). And that also was confirmed by the Finite Difference Time Domain (FDTD) calculation. Moreover, the LSPR would induce the hot charges (polarization charges), which were captured by O2 and H2O molecules to form ROS for photodynamic therapy (PDT). And the heterostructure of Bi and N‑carbon further improved the effective segregation of the hot charges, making the 6.9 times ROS production (Bi@C-2) in comparing with pure Bi sample. In view of the ultrahigh X-ray attenuation coefficient of Bi and great photothermal effect, Bi@N-Carbon@PEG possessed the outstanding computerized tomography (CT) and photothermal imaging capacity. Meanwhile, they also exhibited the favourable biodegradation ability, inducing the elimination via urine and feces within 14 day. The integration of the multi-model (CT and Thermal) imaging and the PTT/PDT/chemotherapy makes Bi@N‑carbon@PEG-DOX to be a potential candidate for cancer treatment.