Green Synthesis of Yellow-fluorescent Carbon Nano-Dots for Cancer-Cell Image and Photocatalytic Inactivation by Using Microplasma

Abstract

In recent years, multifunctional nanoparticles with combined diagnostic and therapeutic functions show great promise in nanomedicine. In this work, we report the environmentally friendly synthesis of fluorescent carbon nano-dots such as carbon quantum dots (CQDs) by microplasma using o-phenylenediamine. The produced CQDs exhibited a wide absorption peaks at 380-500 nm and emitted bright yellow fluorescence with a peak at 550 nm. The CQDs were rapidly taken up by HeLa cancer cells. When excited under blue light, a bright yellow fluorescence signal and intense reactive oxygen species (ROS) were efficiently produced, enabling simultaneous fluorescent cancer cell imaging and photodynamic inactivation, with a 40% decrease in relative cell viability. Furthermore, the CQDs has 98% cell viability at concentrations of 400 μg·mL-1 in the dark demonstrating excellent biocompatibility. The newlyprepared CQDs are thus demonstrated to be materials that can be effectively for imaging-guided cancer therapy.