利用核酸适配体修饰氧化石墨烯复合物的17β-雌二醇检测机理

Bio-Sensing of 17β-Estradiol Using Aptamer Modified Graphene Oxide

为了提高复杂环境水体中雌激素污染的检测性能,通过直接吸附法将核酸适配体固定在氧化石墨烯表面,合成出核酸适配体修饰氧化石墨烯复合物,并将其应用于17β-雌二醇水体污染的高灵敏和特异性均相检测。采用紫外可见分光光谱分析核酸适配体修饰氧化石墨烯复合物,发现该复合物在250nm处有较宽的肩峰,证明核酸适配体成功固定在氧化石墨烯表面。通过荧光分光光度计分析核酸适配体修饰氧化石墨烯复合物与目标物17β-雌二醇反应前后的荧光强度变化,发现荧光强度由峰值110增加到峰值450,表明该复合物可以成功用于对17β-雌二醇的检测,并且荧光强度与17β-雌二醇的质量浓度在10~100μg/L范围内呈正比,最低检出限为6.2μg/L。

In order to improve the detection performance of 17β-estradiol in complex environment water,the aptamer-modified graphene oxide complex was synthesized by immobilization of the aptamer on the surface of graphene oxide with direct adsorption,and it was used for high sensitive and specific homogeneous detection of 17β-estradiol contamination in water.The ultraviolet-visible spectroscopy was used to characterize the aptamer-modified graphene oxide complex.It was found that the complex had a wide peak at 250nm,which proved that the nucleic acid aptamer was successfully immobilized on the surface of graphene oxide.The fluorescence intensity of the aptamer-modified graphene oxide complex before and after reaction with target 17β-estradiol was analyzed by the fluorescence spectrophotometer.It was found that the fluorescence intensities increased from 110to 450,and the relative fluorescence intensities were proportional to the mass concentrations of 17β-estradiol in the range of 10-100μg/L with a minimum detection limit of 6.2μg/L.This indicates that the complex could be successfully used for the detection of 17β-estradiol.