Synthesis,Aggregation-induced Emission Enhancement And BSA Probe Of A New 9,10- Diarylanthracene Derivative

In this article, a new AIEE-active 9,10-diarylanthracene derivative with excellent photophysical properties was synthesized and characterized. The mechanism of its AIEE property was also studied. We prepared two kinds of AIEE dye based nanoparticles, including BSA nanoparticles and silica nanoparticles. The BSA nanoparticles were successfully utilized in HeLa cell imaging and the silica nanoparticles were served as bioprobe to detect BSA. The main results are outlined as follows:1. A new 9,10-diarylanthracene derivative was synthesized by Ullmann reaction and Wittig-Honor reaction with 3,6-bis(tert-butyl)carbazole as branches, triphenylamine as the inner unit and anthracene as the core. The maximum emission wavelength of the compound in solid state was 601 nm and the compound emitted yellow fluorescence. We used THF as the good solvent and water as the poor solvent to investigate the aggregation optical properties of the compound. In pure THF, the fluorescence quantum yield was only 0.06. When the volume fraction of water increased, the fluorescence intensity and the fluorescence quantum yield both increased. When the volume fraction of water increased to 90%, the fluorescence quantum yield reached the maximum of 0.41. Thus, we can conclude that the compound AntCz has the property of aggregation-induced emission enhancement (AIEE). DMF/ glycerol system was selected to study the possible mechanism of AIEE. With the volume fraction of glycerol increased, the fluorescence intensity also increased. When the volume fraction of glycerol was 60%, the intensity was 17-fold higher than that in pure DMF. The UV-vis spectra and fluorescence of AntCz in different solvents were obtained. Bakhshiev’s formula and Kawski-Chamma-Viallet’s formula were used to calculate the dipole moment in the ground state (μg) and the dipole moment in the excited state (μe). Furthermore, the fluorescence spectra of BCPA in solid state and the aggregation optical properties of BCPA in Water/THF were studied.2. We prepared two kinds of AIEE dye based nanoparticles, including BSA nanoparticles and silica nanoparticles. The AIEE dye included AntCz, AnCz,4Py-PAA and 2Py-PAA. Compound AntCz was synthesized according to the method in this article. Compounds AnCz, 4Py-PAA and 2Py-PAA were obtained according to the methods previously reported by our laboratory. The BSA nanoparticles showed high water dispersibility, stable uniform morphology (diameter: around 150 nm), strong fluorescence and excellent biocompatibility. Bright green fluorescence emitted from the chromophores can be seen according to HeLa cell imaging experiments. The silica nanoparticles are of small size (diameter: around 30 nm), monodispersed and stable in aqueous suspension. The surface of the nanoparticles was modified with large number of amino groups. The amino group can reacted with aldehyde group in one side of glutaraldehyde. So the amino groups in the surface of silica nanoparticles were turned into aldehyde groups, which paved way to combine silica nanoparticles with BSA. The AIEE dye based nanoparticles can endow BSA with novel fluorescence properties. The fluorescence spectra of BSA was studied when combined with silica nanoparticles. It was found that the fluorescence intensities of BSA decreased with the increasing of concentrations of silica nanoparticles. The circular dichroism was obtained to assess the secondary secondary structure of BSA.