Rapid Sonochemically-Assisted Synthesis of Highly Stable Gold Nanoparticles as Computed Tomography Contrast Agents

Abstract

One of the most widely used modalities of clinical imaging is computed tomography (CT). Recent reports of new contrast agents toward CT imaging have been numerous. The production of gold nanoparticles (AuNPs) as contrast agents for CT is primarily a topic of intense interest. AuNPs have beneficial features for this application, including excellent X-ray attenuation, flexible sizes and shapes, tailorable surface chemistry, excellent biocompatibility and high levels of contrast generating matter. AuNPs with a size of about 18.5 nm and semi-spherical shape were synthesized using a sonochemical method. The attenuation rate of X-rays as measured in Hounsfield units per unit concentration (HU/mg) was measured. Ultrasound treatment for a duration of five min has been shown to produce highly stable AuNPs in different media (AuNPs in water and phosphate-buffered saline (PBS) was −42.1 mV and −39.5 mV, respectively). The CT value (HU = 395) of the AuNPs increased linearly with an increase in the AuNP dosage. The results confirm the use of ultrasonic treatment for the production of metal nanostructures, particularly highly stable non-toxic AuNPs, with good morphology and high-quality crystal structure using an easy and fast method. Synthesized AuNPs have the potential to be used as a CT contrast agent in medical imaging applications.