Advances in applications of fluorescent probes based on indole heptamethine in Vivo

Abstract

Cyanine dye is a commercially available near-infrared fluorescent dye, its spectral range is in the near infrared region, in this spectrum, absorption or fluorescence intensity of biological sample is very small, so applied cyanine dye to image living body can reduce background interference. Indole heptamethine fluorescent probes which are representative of cyanine dyes are consisted of indole heterocycle, heptamethine and N-substituted side chains. They are widely used for targeted cancer therapy, labling protein, detecting of metal cations and other biological aspects because of their excellent photophysical properties like good solubility, tunable maximum absorption wavelength, large molar extinction coefficient. Based on the structure of indole heptamethine, introducing reactive groups to the parent compounds or changing their structures can make fluorescent probes have different functions like labeling protein and tumour, detecting intracellular metal cations, which has become the hotspot in the field of fluorescence imaging of biological research. Therefore in this paper, the recent progress in the field of applications of indole heptamethine based fluorescent probes for detecting metal cations, changes of pH, molecules and imaging cancer, protein in vivo are reviewed. Besides, the distribution, imaging results and metabolism of probes in vivo (model) have also been elaborated. The biological application trends and problems of this kind of fluorescent probes are also discussed in the end. © 2013 Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences.