Chemical Research in Chinese Universities ›› 2016, Vol. 32 ›› Issue (6): 877-881.doi: 10.1007/s40242-016-6213-4

• Letter • Previous Articles     Next Articles

A pH Sensitive Fluorescence Probe Based on Tricarbocyanine

YAN Luomei1,2, ZHOU Hua1, WU Cunqi1, WANG Lidan1, YANG Wei1, JIN Manyu1,2, ZHAO Yongxia1, XU Jingwei1   

  1. 1. State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China;
    2. University of Chinese Academy of Sciences, Beijing 100049, P. R. China
  • Received:2016-05-20 Revised:2016-09-18 Online:2016-12-01 Published:2016-10-24
  • Contact: ZHAO Yongxia, E-mail:zyx@ciac.ac.cn; XU Jingwei, E-mail:jwxu@ciac.ac.cn E-mail:zyx@ciac.ac.cn;jwxu@ciac.ac.cn
  • Supported by:

    Supported by the State Key Laboratory of Electroanalytical Chemistry of China.

Abstract: A pH sensitive near-infrared (NIR) fluorescent probe, IR-DO3A, was synthesized. It was based on combination of tricarbocyanine that had typical NIR absorption and fluorescent emission spectrum, and DO3A (1,4,7,10-tetra azacyclododecane -1,4,7-triyl)triacetic acid) that had three side chain of carboxylic acids. Phenyl sulfonamide that was used to maintain the density of electronic cloud of tricarbocyanine backbone and improve the solubility of the whole molecule was selected to connect tricarbocyanine and DO3A by several substitution reactions under some certain conditions. The final product, IR-DO3A was confirmed by NMR and MS spectrums, and had a better solubility in polar solvent than tricarbocyanine. The optical properties of IR-DO3A in two mixture solvents were studied. It had maximum Uv-vis absorption at 750nm and 805nm, fluorescent emission at 808nm, all these wavelengths were in NIR range and there was a 58nm Stokes-Shift. Also its optical properties at different pH in water were studied and it was sensitive in pH 6~9, which related with the protonation and deprotonation processes of IR-DO3A at different pH. These pH sensitive and NIR-fluorescent properties may result in an application for revealing the pH changes of physiological diseases.

Key words: pH sensitive probe, Near-infrared fluorescence emission, Tricarbocyanine