一种基于适配体传感器的17β-雌二醇定量分析方法

A quantitative analysis method for 17β-estradiol based on aptasensor

为了灵敏、特异地测定牛奶中17β-雌二醇(E2)的含量,解决传统方法测定时因原位激发导致的荧光背景干扰、样品预处理复杂等问题,基于荧光共振能量转移(FRET)原理,结合适配体与靶标的特异性识别,建立一种基于荧光适配体传感器的E2定量分析方法。采用水热合成法制备铕(Eu3+)掺杂的镓酸锌长余辉纳米粒子,并将E2适配体修饰到纳米粒子(PLNP)上,形成复合物(PLNP-Aptamer)。以PLNP-Aptamer为能量供体,以二硫化钼纳米片为能量受体,根据荧光强度与靶标17β-雌二醇之间的线性关系实现对E2的检测,并对检测条件进行优化。结果表明,当PLNP-Aptamer、二硫化钼的质量浓度分别为0.1,0.8 mg/mL,E2与适配体的孵育时间为20 min,pH值为7.0时,雌二醇的线性检测范围为0.6~80 ng/mL,检出限为0.4 ng/mL。通过加标回收实验,证明检测体系对17β-雌二醇具有显著的选择性,可用于实际样品的检测。所提方法解决了样品预处理复杂耗时,乳基质荧光干扰等问题,可为基层卫生监督工作提供一种简单、高效、成本低廉的雌激素检测方法,对其他环境雌激素的检测也具有参考价值和借鉴意义。

In order to determine the content of 17β-estradiol(E2)in milk sensitively and specifically,and solve the problems such as the interference of fluorescence background caused by in-situ excitation and the complexity of sample pretreatment in the traditional method,a quantitative analysis method for 17β-estradiol based on fluorescence aptasensor was constructed on grounds of the fluorescence resonance energy transfer(FRET),combined with the specificity of the aptamer and target recognition.Persistent luminescence nanoparticles(PLNP)doped with Eu3+were prepared by the hydrothermal method and modified with E2 aptamers onto PLNP to form the coupling complex PLNP-Aptamer.In this method,PLNP-Aptamer was used as energy donor.MoS2 was used as the acceptor.According to the linear relationship between phosphorescent intensity and target E2,the content of E2 was detected,and the detection conditions were optimized.The results show that when the concentrations of PLNP-Aptamer and MoS2 are 0.1 mg/mL and 0.8 mg/mL respectively,the reaction time of E2 and aptamer is 20 min,pH is 7.0,the linear detection scope of E2 concentration is from 0.6 ng/mL to 80 ng/mL and the detection limit is 0.4 ng/mL.The adding standard recovery experiment proves that the detection system has high specificity to E2,and can realize quantitative detection of E2 in actual samples.The method provides a simple,efficient and low-cost estrogen detection method for grass-roots health supervision by solving the problem of the complicated time-consuming of sample pretreatment and avoiding the fluorescence interference of milk matrix.It also provides a reference for other environmental estrogens detection.