Synthesis of ternary copolymer nanoparticles including fluorescein and their fluorescent property

    FENG Aiª²Ling1,WU Daoª²Cheng2,WU Hong1£¬YANG Qingª²Yan1

    1Department of Chemistry,School of Pharmacology,Fourth Military Medical University,Xi¬ðan 710033,China,2School of Biomedical Engineering,Xi¬ðan Jiaotong University,Xi¬ðan 710038,China

    ¡¾Abstract¡¿ AIM: To synthesize the ternary copolymer microspheres Styreneª²Acrylamideª²Acrylic acid (Stª²Aamª²AA) including fluorescein and to study their properties.METHODS: The ternary fluorescent copolymer microspheres were synthesized by means of emulsifierª²free emulsion polymerization.The effects of different factors on property of polymer were evaluated by using orthogonalª²designing table L18 (37).Five factors with three levels were considered in the experiment,namely,temperature,agitating rate,the value of pH,ionic strength and reacting time.Morphological and size analysis of latex was conducted by transmission electron microscopy (TEM) and atom force microscopy (AFM),and the sizes were measured.Fluorescence spectrophotometer was used to determine the fluorescent property.RESULTS: When temperature was 75¡æ,the agitating rate was 300 r/min,the value of pH 7ª±5,the amount of NaCl 0ª±5 g and the reacting time 4 h.The synthesized latices with highª²stability and goodª²fluorescence were monodispersed,and the maximum exciting wavelength and emitting wavelength were 551ª±7 nm and 554ª±2 nm respectively.The strongest fluorescent intensity of microspheres was observed when the pH value was 6ª±0.The fluorescein release experiment of microspheres showed that the latices were stabler at 4¡æ than at 25¡æ.CONCLUSION: The ternary copolymer nanoparticles including fluorescein have good fluorescent characteristics. ......