荧光胺定量检测纳米SiO_2表面氨基的含量

Quantitative Detection of Amino Groups on Silica Nanoparticle Surfaces Using Fluorescamine

首先用3-氨丙基三乙氧基硅烷偶联剂(APTES)在一定条件下接枝于纳米二氧化硅表面,并采用傅里叶变换红外光谱仪(FI-IR)进行测试表征,建立了一种用荧光胺定量检测功能化纳米SiO_2表面氨基的方法,并通过优化实验建立该检测方法的测试标准。最佳检测条件为:室温下,激发波长380 nm、发射波长480 nm,荧光胺的丙酮溶液与磷酸盐缓冲液体积比1∶5,磷酸盐缓冲液pH值为10.0,反应时间为10 min等条件下,荧光信号最稳定。采用该最佳条件下制定的标准曲线对功能化纳米SiO_2微球进行检测,结果符合预期,该方法检测灵敏度高、操作简单。

The surface of nano SiO2 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.