Acta Chim. Sinica ›› 2018, Vol. 76 ›› Issue (9): 709-714.DOI: 10.6023/A18060225 Previous Articles     Next Articles



张燕燕a, 武明豪a, 武明杰b, 国林沛c, 曹琳a, 吴虹仪a, 张雪宁a   

  1. a 天津医科大学第二医院 医学影像科 天津 300211;
    b 加拿大国家科学研究院 能源材料研究所 加拿大 J3X1S2;
    c 天津医科大学第二医院 泌尿外科研究所 天津 300211
  • 投稿日期:2018-06-05 发布日期:2018-07-23
  • 通讯作者: 张雪宁
  • 基金资助:


Study of Fluorescence and CT Bimodal Imaging of Ultrasmall Gold Nanoclusters

Zhang Yanyana, Wu Minghaoa, Wu Mingjieb, Guo Linpeic, Cao Lina, Wu Hongyia, Zhang Xueninga   

  1. a Department of Medical Imaging, Second Hospital of Tianjin Medical University, Tianjin 300211;
    b National Institute of Scientific Research-Energy Materials and Telecommunications, Canada J3X1S2;
    c Institute of Urology, Second Hospital of Tianjin Medical University, Tianjin 300211
  • Received:2018-06-05 Published:2018-07-23
  • Contact: 10.6023/A18060225
  • Supported by:

    Project supported by the Program of the Tianjin Health and Family Planning Commission (No. 16KG115) and the Tianjin Medical University "13th Five-Year" Comprehensive Investment Subject Construction Project (No. 116015012017XK0202).

Multimodality imaging can integrate structural/functional information from different imaging tools, thus provide more accurate diagnosis than each single imaging modality. Au nanoclusters (AuNCs) are unique and have rich X-ray attenuation and fluorescent properties based on strong quantum confinement effect (SQCE); however, there is a huge challenge to simultaneously improve both X-ray imaging ability and fluorescent properties by adjusting sizes under the requirements of in vivo biological application. In this study, using rGSH as reductant and stabilizer, we developed a sub-nanometer ultrasmall AuNCs (Us-Au15NCs) as an optimized multimodal imaging probe with enhanced imaging ability by accurately adjusting pH to 8. For the first time, the in vitro both enhanced fluorescent and X-ray computed tomography (CT) bimodal imaging ability of AuNCs were investigated. By adjusting the pH and the proportion of Au3+ ions to GSH, the fluorescence intensity of the Us-AuNCs was strengthened and the emission peak showed red-shifts from 510 nm to 683 nm. While promising and exciting, the attenuation coefficient verified by the HU (hounsfield unit) values was increased almost linearly with the ratio increasing, which preserved the excellent X-ray imaging ability of Us-AuNCs. In addition, With a demonstrated better X-ray attenuation property than that of clinically used iodinated small molecular contrast agent (e.g., Iohexol), the developed Us-Au15NCs enabled efficient and enhanced CT imaging. Thus, the synthesized Us-Au15NCs characterised by UV-vis spectra and fluorescence spectra could simultaneously possess superior CT contrast ability and significant photoluminescence properties. Transmission electron microscopy (TEM) results revealed that the morphology was uniform spherical shape. Moreover, the Us-Au15NCs shows excellent stability, low cytotoxicity and good biocompatibility. Furthermore, the prepared Us-Au15NCs was confirmed to be effective and applicable for fluorescent imaging of 4T1 tumor cells, which determining that the Us-Au15NCs was more effectively involved with the cancer cells. The significance of this study is that rather than the synthesis of Us-AuNCs only, the prepared Us-Au15NCs may serve as multimodality imaging contrast agent with fluorescence and CT imaging for clinical diagnosis application.

Key words: ultrasmall AuNCs, fluorescence imaging, CT imaging, bimodal imaging