Water-dispersible ultrasmall nanogolds (WDU AuNPs) and their dopamine-coated nanogolds (WDU AuNPs@DPAs) were prepared by a reduction method with sodium borohydride as a reducing agent and a stabilised agent of 2-mercaptosuccinic acid in aqueous solution. The effects of these nanoparticles on computed tomography (CT) imaging were evaluated. The size distributions and Zeta potential of the nanoparticles were measured with a Malvern size analyser, and nanoparticle morphology was observed by transmission electron microscopy. These characteristics were confirmed by Fourier transform spectroscopy and ultraviolet/visible spectra. It was found that WDU AuNPs@DPAs were 5.4 nm in size with clear core–shell structure. The 3-(4, 5-Dimethyl-2-thiazolyl)-2, 5-diphenyltetrazolium bromide assay results showed that the WDU AuNPs and WDU AuNPs@DPAs were hypotoxic to different cells. The WDU AuNPs@DPAs showed a much longer circulation time and a larger CT attenuation coefficient than iohexol and could be excreted by the kidney and bladder. These nanoparticles showed considerable potential for future application in CT imaging.

采用硼氢化钠作为还原剂和2-巯基琥珀酸在水溶液中的稳定剂，通过还原法制备了水分散性超小纳米金（WDU AuNPs）及其多巴胺包覆的纳米金（WDU AuNPs @ DPAs）。评估了这些纳米粒子对计算机断层扫描（CT）成像的影响。用Malvern尺寸分析仪测量纳米颗粒的尺寸分布和Zeta电位，并通过透射电子显微镜观察纳米颗粒的形态。这些特征通过傅里叶变换光谱和紫外/可见光谱证实。发现WDU AuNPs @ DPA的大小为5.4 nm，具有清晰的核壳结构。3-（4，5-二甲基-2-噻唑基）-2，5-二苯基溴化四氮唑测定结果表明，WDU AuNPs和WDU AuNPs @ DPA对不同细胞均具有低毒性。与碘海醇相比，WDU AuNPs @ DPA具有更长的循环时间和更大的CT衰减系数，可以被肾脏和膀胱排泄。这些纳米粒子显示出巨大的潜力，可用于将来在CT成像中的应用。