Synthesis, crystal structure, optical properties, DNA-binding and cell imaging of an organic chromophore

An organic chromophore (4-[N, N- bis(2′-chloroethyl)anilino] ethenyl N-methyl pyridinium-N- methyl iodide) L was synthesized and fully characterized by elemental analysis, IR, 1HNMR spectra and single crystal X-ray diffraction analysis. One and two-photon fluorescence spectra for it were studied. Interestingly, L exhibited obvious two-photon absorption in the range from 700–850 nm in DMSO solution. The interactions between the chromophore and calf thymus DNA were investigated by absorption, fluorescence spectra and viscosity experiments. The results showed that the chromophore could interact with DNA in the mode of intercalation and be effectively used as fluorescent staining dye for cell imaging applications. Furthermore, the cell viability data for MCF-7 (Human breast carcinoma) cells indicated that the low-micromolar concentrations of the L are essentially non-toxic and can be applied in brighter two-photon fluorescent (TPF) bioimaging.

Graphical abstractAn organic chromophore was synthesized and fully characterized by elemental analyses, IR, 1HNMR spectra and single crystal X-ray diffraction analysis. one and two-photon absorption properties, DNA-binding, and cell imaging of the new chromophore were investigated systematically. Interestingly, the chromophore exhibits obvious two-photon absorption in the range from 700–850 nm in DMSO solution, and be effectively used as fluorescent probes for cell imaging applications.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► An organic chromophore was synthesized and fully characterized. ► The interactions between the chromophore and ctDNA in the mode of intercalation. ► The chromophore exhibits obvious two-photon absorption in NIR region in DMSO solution. ► The chromophore can be used as fluorescent staining dye for cell imaging applications.