Economical synthesis of ultra-small Bi 2 S 3 nanoparticles for high-sensitive CT imaging

Ultra-small Bi2S3 nanoparticles are potential contrast agents for high-sensitive CT imaging. However, the expensive and harmful synthesis process limited their further application. Herein, an economical and low-toxic process was developed by employing S powders as sulfur precursors for large-scale preparation of ultra-small Bi2S3 nanoparticles. The as-prepared ultra-small Bi2S3 nanoparticles were modified with amine-terminated poly(ethylene glycol) (PEG) to produce water-soluble contrast agents. In vitro experiment results suggested that the ultra-small Bi2S3-PEG nanoparticles were low cytotoxic and superior contrast agents. In vivo experiments demonstrated that the ultra-small Bi2S3-PEG nanoparticles were preferred contrast agents for long-term and high-sensitive CT imaging.