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Updated: Nov 2, 2025
Computed Tomography-guided Time-domain Diffuse Fluorescence Tomography in Small Animals for Localization of Cancer Biomarkers
Published on: July 17, 2012
A near-infrared fluorescent probe with large Stokes shift for imaging Cys in tumor mice
Juan Liu1, Zhi-Qing Wang1, Guo-Jiang Mao2
1Key Laboratory for Green Organic Synthesis and Application of Hunan Province, Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of Education, College of Chemistry, Xiangtan University, Xiangtan, 411105, PR China.
Abstract:
Cysteine (Cys), a kind of small molecule biological thiol, not only involves in the regulation of physiological processes, but also is considered a marker of tumor. However, it is challenging to develop suitable probe for detecting Cys in tumors. In this paper, a near-infrared (NIR) fluorescent probe named IX for Cys has been designed and synthesized. The probe shows a NIR emission peak at 770 nm with large Stokes shift (180 nm) upon adding Cys. It displays high sensitivity to Cys with 6-fold increase of fluorescence intensity. Meanwhile, IX has the high selectivity to Cys over other potential interference such as Hcy and GSH, which have similar structure with Cys. In addition, a possible mechanism of fluorescence enhancement is the reaction of IX with Cys to release IX-OH, which is verified by fluorescence spectra, MS and HPLC. Next, IX can selectively image Cys in HCT-116 cells thanks to the low cytotoxicity. Most important of all, the fluorescent probe IX has visualized Cys in HCT116-xenograft tumor mice due to the near-infrared properties with large Stokes shift.
