Synthesis Of Carbazole-based Two-photon Fluorescent Probes And The Application In Cell Imaging

In recent years, two-photon fluorescent imaging technology as a new nonlinear optical imaging method has been widely used in long-time dynamic3D imaging of living cells and tissues, and developed fast. More and more life scientists know the advantages of this technology, like the lower cell damage, larger imaging depth, lower background noise and the ability to image living cells for a long time and so on. Two-photon fluorescent probes related with this technique become the focus of the material scientists who try to maximize the applications of the two-photon fluorescent microscopy.The technology of fluorescent imaging is mainly used in the imaging of cell, tissues, and vivo imaging. Among them, cell is the basic biological research of life science. There are large numbers of fluorescent probes used in one-photon fluorescent confocal imaging, and many of them have been commercialized and widely used in relative fields. Many new probes targeting molecules, organelles, signals, and other structures are being reported. But probes for two-photon fluorescent microscopy are lack, and there are many problems need to be overcome. Finding new probes with better two-photon properties is an urgent issue for scientists. In this paper, by using the conjugation of the carbazole derivatives, we synthesized several probes with two-photon properties, and they targeted the organelles:the mitochondria or nucleus and the lysosome.With positive charge, pyridine cationic salt can interact with some charged molecules or structure in cells. Many fluorescent probes were designed and synthesized according to this, including mitochondria and nucleic acid probes. Mitochondrion is the place for intracellular oxidative phosphorylation and calcium ion storage. It plays an important role in cell life. The nucleus, which is the largest, most obvious and most important organelle of the eukaryotic cells, and it is the place that the nucleic acid, the carrier of genetic information, widely distributed. At present, there are large numbers of the probes targeting the mitochondrion or nuleus, both commercial and reported. But these probes can turn-on the mitochondrion only in living cell or fixed cell or combined with some compound or ion in the mitochondrion. In this paper, we will introduce a probe with two-photon properties and the probe can image the mitochondrion in living cell and the nucleus in dead cell. We measured the fluorescent spectra about the effects of DNA/RNA, the solvents. For the cell imaging, we observed the location of the probe in cells, and co-localized with commercial probes. All the experiments concluded the utilization of the probe.Pyridine and benzimidazole, containing unsaturated N, can protonized easily. So they can be used to identify the acidic environment. Organelle like lysosomes with rich proton can be detected by this class of molecules. Lysosome contains a variety of acid hydrolases, and it makes great importance for the normal metabolism maintenance and resistance of the microorganism. Presently, probes about the lysosome and the acidic pH ranges have been reported and used. And in this paper, we will introduce a new probe targeting the lysosome with two-photon properties. We measured its fluorescent spectra under different pH and solvents, and excluded the disruption of some small molecules and ions. And we also did the fluorescent imaging experiment in the intracellular. The imaging included the co-staining with the commercial probes to infer the location. According to the experiences, we concluded the selectivity and the proper utility of the probe.In this paper, the probes introduced are based on carbazole, and we got the organic compounds by using mature chemical reactions. All the compounds are characterized by organic analysis, including’H NMR,13C NMR, high resolution mass spectrometry and infrared spectroscopy. The spectra we did included UV-visible absorption spectra, one-photon fluorescent spectra and two-photon spectra. About the images, we used fluorescent confocal and two-photon fluorescence microscopy to get the pictures of the stained cells. It turned out that the probes we got can did something for the cell imaging according to all the experiments.