关键词: 荧光胺;定量检测;纳米SiO2;氨基含量

Abstract: The surface of nano SiO 2 particles was modified by silane coupling agent 3-aminopropyltriethoxysilane ( APTES ) under the definite reaction conditions , then the structure of modified silica nanoparticles were characterized by Fourier Transform Infrared Spectrum ( FTIR ) .A simple and highly sensitive fluorimetric method has been developed for the quantitative determination of surface amino groups of modified silica nanoparticles , and established a quantitative detection standard set curve under the optimum conditions .The fluorimetric method was based on nucleophilic substitution reaction of APTES with fluorescamine ( FLC) .It is shown that highly fluorescent signal was measured at 480 nm after excitation at 380 nm on the volume ratio of FLC acetone solution with phosphate buffer liquid of 1:5 at room temperature, the fluorescent signal is utmost stable with pH of 10.0, reaction time of 10 min in the testing system , adopting the optimum standard method for testing , the results agreement with theoretical values .The detection method of amino groups on modified silica nanoparticle surfaces based on FLC is fast , high accuracy and simplicity of operator .

Key words: fluorescamine;quantitative detection;silica nanoparticle;amino group content