The ASE And SERS Of Fluorene Fluorescent-dye-doped DNA-CTMA Thin Films

The photoelectric property of optoelectronic devices which are made of DNA materials.Asthe unique double helix, the doped substrate of DNA molecule show the excellent space stericproperties. The fluorescence quantum yield and the stimulated radiation section of fluorenefluorescent material which are easy to be synthetized and modified are very large.On the otherhand, the surface enhanced Raman scattering which is by the noble metal nanoparticles is of greatsignificance in the field of biological detection. In this paper, the4-(9,9-diethyl-2-(pyridin-4-yl)-9-H-fluoren-7-yl) pyridine (DPFP) was synthesized via a Suzuki coupling reaction. The DNA-CTMA material of was by a ion exchange reaction. The amplified spontaneous emission(ASE) ofthe DPFP-DNA-CTMA thin film was studied experimentally by pumping of pulse laser with awavelength of355nm.The surface enhanced Raman scattering characteristics of gold-nanoparticles–doped DNA-CTMA-DPFP film which was studied.This paper includes five parts. In the first chapter, the fluorine fluorescent material and thephotoelectric characteristics of DNA biological materials and the SERS substrate research progressare reviewed. In the second chapter, according to the principle of laser and the thin film waveguidetheory, when the film under the laser pumped, the dye molecules that are population level inversionproduce radiation. The stimulated radiation was amplificated by the light of spontaneous emission,transmiting within the waveguide. According to the classical theory of electromagnetic radiationwe introduce electromagnetic field used precious metals SERS enhancement and the chemicalenhancement principle. In the third chaper, the DPFP dye synthetized by Palladium catalyticSuzuki, the absorption spectrum of the DPFP is located in the260-360nm near ultraviolet band, thefluorescence spectrum in350-450nm, two fluorescent peak are at370and386nm, a shoulder peakat408nm, three vibronic transitions from an excited stateof S1to the ground state of S0level. Fourkinds of doping ratio of DPFP-DNA-CTMA thin film samples were preparated, the thin films werepumped by a nanosecond Nd：YAG laser, the ASE characteristic of the thin film samples wastested, the threshold energy densities are3.24and3.40mJ/cm2, respectively, the ASE peaks ofDPFP-DNA-CTMA thin films are located390and406nm. By adjusting the doped proportion ofDPFP in DNA-CTMA, ASE can be realized at a specific wavelength. DPFP-DNA-CTMA is akind of good laser material. In the four chapter, the gold nanoparticles was preparated by sodiumcitrate reduction of chloroauric acid, the gold nanoparticles and DNA-CTMA materials were combinated, four kind of gold nanoparticles doped DNA-CTMA and DNA-CTMA substrate. wereby self-assemblied. The Raman spectra of DPFP dye molecule in the film samples were excited bya laser with the wavelength785nm, and the SERS peak intensities of DPFP molecule graduallyincrease as the increase of gold nanoparticles doped into the DNA-CTMA complexes. Therefore,the gold-nanoparticles-doped DNA-CTMA films are suitable as the SERS substrates of many dyemolecules.The fifth chapter is the summary of the full paper.