46results about How to "Fluorescent properties are stable" patented technology

The invention relates to a germanium fluorescent cluster, a preparation method of the germanium fluorescent cluster in aqueous solution and its application in biological imaging. The synthesis method uses germanium dioxide as germanium source, biomolecular cysteine ​​as protective agent, and sodium borohydride as reducing agent to prepare monomolecular-layer protected germanium nanoclusters with fluorescent properties. The raw materials used in the present invention are simple, easy to obtain, stable in nature, and non-toxic; the reaction process does not require the protection of high temperature and inert gas, and is simple and easy to operate; the obtained germanium quantum dots with emerald green or yellow fluorescence are in phase with the previously reported noble metal nanoclusters. It has a higher fluorescence quantum yield, and the cluster size is about 1nm. It has good water solubility and no cytotoxicity, and can be well applied to biological cell imaging.

The invention provides a method and product for preparing autofluorescence polystyrene material, which is characterized in that on the surface of polystyrene material, especially on the surface of polystyrene microspheres, it is acylated by Friedel-Crafts under the action of an acidic catalyst (Alkylation) reaction introduces small molecule color-producing (color-aiding) functional groups, which form π-π (p-π) conjugation with the large π bond of the benzene ring to form a conjugated system, which undergoes electronic transition under the action of excitation light Produce fluorescence. Under the excitation of 405nm laser, the prepared polystyrene fluorescent microspheres can produce obvious fluorescent signals in the blue, green and orange channels of the laser confocal microscope. At the same time, we found that the introduction of electron-withdrawing groups on the conjugated substituents can red-shift the emission peak of polystyrene materials. The preparation method of the invention is simple, high in efficiency and low in cost. The prepared autofluorescent polystyrene microspheres have the characteristics of high fluorescence intensity, stable chemical properties, no fluorescence leakage, high mechanical strength, etc., and have great application potential in the fields of biomedicine and electronic light-emitting devices.

According to the cyclic amidinyl fluorescent molecule with the same-side push-pull electron effect described in the present invention, the structural formula of the fluorescent molecule is: the cyclic amidinyl fluorescent molecule contains both an electron-pushing group (EDG) and an electron-withdrawing group (EWG). ), thereby constructing a novel skeleton molecule with a 10π electron structure, in which the electron-pushing group and the electron-withdrawing group are on the same side of the π electron, and this structure has a large Stokes shift (approximately 100nm), excellent acid-base stability, and stable fluorescent properties in the pH range of 2.8-11.4. At the same time, the fluorescent molecule has no obvious cytotoxicity and has broad biological application prospects. A preparation method of the fluorescent molecule is also disclosed. The method has simple process, mild conditions and is suitable for industrial batch production.

The invention discloses a method for measuring cellular oxidative stress damages under ionizing radiation by using fluorescent protein as a fluorescence probe. The content of free radicals generated in ionizing radiation is quantitatively measured by using the fluorescent protein which is selectively positioned and expressed on a subcellular structure sensitive to the ionizing radiation, so that the damages of the ionizing radiation on the specific positions of a cell are speculated by directly observing the fluorescence intensity change of the protein. By the method, the emitted fluorescence is easy to detect, has high sensitivity, stable fluorescence properties, can normally emit light in a wider pH range, has higher resistance to high temperatures, detergents, salt, organic solvents and most ordinary enzymes, is not toxic to the cell, is not interfered by false positive, makes vector construction convenient and is expressed without specificities of species, tissues and positions.