Core@shell nanoparticles (Fe₃O₄@Au CSNPs) have multiple functions obtained in one stable entity and thus have been extensively investigated. Fe₃O₄ NPs have unique superparamagnetic properties which allow for their application in different fields, and Au NPs stand out in biomedical applications because of their chemical stability, oxidation resistance and high-quality intrinsic optical properties. Combining Fe₃O₄ and Au NPs in one core@shell nanostructure is a promising strategy for diagnostic biomedical applications. However, the conventional direct methods for Fe₃O₄@Au CSNP synthesis are laborious and time consuming. Therefore, this study presents a facile and rapid sonochemical technique of synthesising Fe₃O₄@Au CNPs with excellent physicochemical properties for magnetic resonance imaging (MRI) and computed tomography (CT) scan. A Vibra Cell ultrasonic solid horn with a tip size of ½ inch, 20 kHz frequency and power output of 750 W were used, and the synthesis is achieved in just 10 min. Several techniques were used to characterise the Fe₃O₄@Au CSNPs and confirmed their average size of 21 nm and the formation of spherical Au shell on the Fe₃O₄ core. The Fe₃O₄@Au CNPs showed good biocompatibility and great potential as a dual-mode contrast agent for MRI/CT imaging. The transverse relaxivity values and X-ray attenuation of the as-synthesised NPs (222.28 mM⁻¹s⁻¹ and HU = 418) are greater than those of NPs prepared using conventional methods and commercial NPs. This work reveals considerable progress on Fe₃O₄@Au CSNPs by providing a facile and rapid method to synthesise high-quality Au-coated Fe₃O₄ NPs.

核壳纳米粒子（Fe ₃ O ₄ @Au CSNP）在一个稳定的实体中具有多种功能，因此已得到广泛研究。Fe ₃ O ₄ NP具有独特的超顺磁性质，可用于不同领域，而Au NP由于其化学稳定性，抗氧化性和高质量的固有光学性能而在生物医学应用中脱颖而出。在一个核壳纳米结构中结合Fe ₃ O ₄和Au NP是一种有前景的诊断生物医学应用策略。然而，常规的直接方法Fe ₃ O ₄@Au CSNP合成费力且费时。因此，本研究提出了一种简便，快速的声化学技术，用于合成具有优异物理化学性质的Fe ₃ O ₄ @Au CNP，用于磁共振成像（MRI）和计算机断层扫描（CT）扫描。使用了具有½英寸尖端尺寸，20 kHz频率和750 W功率输出的Vibra Cell超声固体喇叭，并且仅在10分钟内即可完成合成。使用了几种技术来表征Fe ₃ O ₄ @Au CSNP，并确认了它们的平均大小为21 nm，并在Fe ₃ O ₄核上形成了球形Au壳。铁₃ O ₄@Au CNPs具有良好的生物相容性，作为MRI / CT成像的双模造影剂具有巨大的潜力。合成后的NP的横向弛豫值和X射线衰减（222.28 mM ^-1 s ^-1和HU = 418）大于使用常规方法和商业NP制备的NP。这项工作揭示了Fe ₃ O ₄ @Au CSNPs的重要进展，因为它提供了一种简便而快速的方法来合成高质量的Au包覆的Fe ₃ O ₄ NPs。