Synthesis and toxicity testing of cysteine-functionalized single-walled carbon nanotubes with Caenorhabditis elegans†
As carbon nanotubes are incorporated into commercial products in ever-increasing amounts, it is important to produce nontoxic nanotubes and have a reliable method for testing their toxicity. This article reports the synthesis and characterization of cysteine-functionalized single-walled carbon nanotubes and the usefulness of toxicity tests employing the nematode Caenorhabditis elegans. The cysteine-functionalized nanotubes have good aqueous solubility and are nontoxic to C. elegans. Additionally, the cysteine-functionalized nanotubes are shown to be capable of delivering a pharmaceutical compound through a cleavable disulfide bond. This work presents a straightforward synthesis of an easily synthesized, biocompatible carbon nanotube that will have applications in biomedicine.