Economical Synthesis of Carbon Nanoparticles

Abstract

A simple and eco-friendly approach that employs a domestic pressure cooker as an inexpensive hydrothermal reactor for the batch synthesis of water-soluble, photoluminescent nanoscale carbon dots derived from benign and cheap commercial starting materials. The resulting carbon nanodots, which consist primarily of hydrophile-decorated amorphous carbon and boast bright, stable, excitation wavelength-dependent fluorescence, were shown to be viable cellular imaging agents for mice embryonic fibroblast cells, displaying little or no cytotoxicity for carbon dot concentrations up to 0.667 mg/mL. In addition, the carbon dots proved useful as nanoprobes for the fluorescence-based detection of environmentally-relevant heavy metal ions such as Cu²⁺, displaying detection limits below 6 μM, sufficient to determine potable water safety (20 μM is the limit for safe drinking water set by the U.S. Environmental Protection Agency). More generally, these results highlight the utility of a household pressure cooker as a cost-effective hydrothermal vessel relevant to nanocarbon synthesis, opening other possibilities for nano synthesis, particularly in resource-limited settings, educational venues, and the classroom itself.