Bismuth Sulfide Nanostructures as Contrast Agents for Computed Tomography

CT contrast agents based on iodinated compounds have been studied for imaging since 1920s. Despite effective attenuation, versatile synthesis methods and body tissue tolerance, these agents suffer from limitation in circulation times (<10 min) that results in poor contrast. Bismuth sulfide nanoparticles have circulation times up to 140 min¹. Also their high X-ray attenuation and low cost make them good candidates for X-ray-based imaging.
In this work, a chemical methodology for the synthesis of uniform Bi₂S₃ nanostructures is reported. The reaction is in a mixture of primary (oleylamine) and tertiary (trioctylamine) solution at moderate temperature (<200^oC) using Bi(Ac)₃ as Bi3+ source. XRD analysis shows the single phase Bi₂S₃ nanoparticles, while TEM measurements used for the morphological characterization. Both amines are important for the structural and morphological control of the synthesized materials. Additionally, by changing the molecular ratio of the amines we are able to control shape and size of the particles. Our goal is to coat the Bi₂S₃ nanorods with Fe₃O₄ nanoparticles to produce a multifunctional contrast agent for CT and MRI scans.
¹Rabin O,Perez JM,Grimm J,Wojtkiewicz G,Weissleder R (2006)