Gold (Au) is expected to function as a high contrast agent for X-ray computed tomography imaging as it has high X-ray absorptivity owing to a large atomic number compared to commercial materials such as barium and iodine. In addition, Au formation with a nanorod structure (AuNR) can be used for hyperthermia because of the enhancement of the photothermal reaction effect. The present work proposes a preparation method for core–shell nanoparticles composed of AuNR, SiO₂, and a single nanometer-sized Au (sAu), toward imaging and photothermal therapy. The AuNRs (lateral size: 12.6 nm; longitudinal size: 44.9 nm) were silica-coated using a sol–gel method with tetraethyl orthosilicate, which produced AuNR/SiO₂ nanoparticles with an average size of 86.9 nm. Thiol groups were introduced onto the AuNR/SiO₂ nanoparticle surface by using (3-mercaptopropyl) trimethoxysilane (AuNR/SiO₂-SH). The sAu nanoparticles (particle size: 2.6 nm) were produced by adding tetrakis (hydroxymethyl) phosphonium chloride as a reductant and HAuCl₄ (aq) to NaOH solution. A thiol-terminated PEG (PEG-SH) aqueous solution and sAu nanoparticle colloidal solution were added in turn to the AuNR/SiO₂-SH dispersed in EtOH (AuNR/SiO₂/sAu-PEG). The CT value of the AuNR/SiO₂/sAu-PEG particle solution was 702 HU. The CT values in tissues immediately increased after injection into mouse. Their blood retention times were 3–6 h, much longer than the few minutes of a commercial X-ray contrast agent (Iopamiron).

预计金（Au）会用作X射线计算机断层扫描成像的高对比剂，因为与商业材料（如钡和碘）相比，由于原子数​​大，它具有高的X射线吸收率。另外，由于增强了光热反应效果，具有纳米棒结构的Au形成（AuNR）可用于热疗。本工作为成像和光热疗法提出了一种由AuNR，SiO ₂和单纳米级Au（sAu）组成的核-壳纳米粒子的制备方法。使用溶胶-凝胶法用原硅酸四乙酯对AuNRs（横向尺寸：12.6 nm；纵向尺寸：44.9 nm）进行二氧化硅涂覆，从而生成AuNR / SiO ₂平均尺寸为86.9 nm的纳米颗粒。通过使用（3-巯基丙基）三甲氧基硅烷（AuNR / SiO ₂ -SH）将硫醇基团引入AuNR / SiO ₂纳米颗粒表面。通过将四（羟甲基）氯化chloride作为还原剂和HAuCl ₄（水溶液）添加到NaOH溶液中，制得sAu纳米颗粒（粒径：2.6 nm）。将巯基封端的PEG（PEG-SH）水溶液和sAu纳米胶体溶液依次添加到分散在EtOH中的AuNR / SiO ₂ -SH（AuNR / SiO ₂ / sAu-PEG）中。AuNR / SiO ₂的CT值/ sAu-PEG颗粒溶液为702 HU。注入小鼠后，组织中的CT值立即增加。它们的血液保留时间为3–6小时，比商业X射线造影剂（碘帕龙）的几分钟长得多。