Abstract: Near-infrared fluorescence technology has been applied in biomarkers, bioanalysis, cell imaging and bio-tissue imaging in vivo. Especially the fact that organisms have low scattering effect and background interference in near-infrared region, increases near-infrared image sensitivity and penetrating depth in biological tissue.  Near-infrared fluorescence agents are promising reagent for detection and imaging in deep tissues and organs. Porphyrins have extension electronic conjugated structure, good optical stability, acceptable fluorescent quantum yields, and good biocompatibility, which endow porphyrins with near-infrared emission have more advantages than other dyes in fluorescence imaging. In this paper, bis{[5,5'-10,20-bis(phenyl)-15(4-pyridyl)porphyrin]zinc(Ⅱ)} butadiyne was designed and synthesized as near-infrared fluorescent compound. The structures of the compounds were confirmed by means of 1H NMR and MS. UV-Vis spectra were measured by spectral method and fluorescence imaging was recorded by HWHR optical instrument.  Deep fluorescence imaging in vitro was studied with biotissue as model. The results show that bis{[5,5'-10,20-bis(phenyl)-15(4-pyridyl)porphyrin]zinc(Ⅱ)} butadiyne has strong fluorescence in near-infrared region. Fluorescence imaging of biotissue in vitro can achieve structural information in a depth more than 1 cm.  So this butadiyne linked prohyrin dimmer partially meets the demand of near-infrared imaging and can be potentially applied in the fluorescence imaging diagnosis in vivo in future.

Key words: Porphyrin, Near-infrared, Fluorescence imaging, Biotissue