时间分辨荧光侧流分析法检测水中17β-雌二醇

Detection of 17β-Estradiol in Water by Time-resolved Fluorescence Lateral Flow Assay

以偶联17β-雌二醇包被原(E2-BSA)的长余辉粒子(PLPs)为荧光供体,胶体金标记抗体为荧光受体,基于免疫识别和荧光共振能量转移原理,建立了E2的竞争型时间分辨荧光侧流分析方法。创新性地以余辉优良、微米级大尺寸的PLPs为荧光信号源,并利用其在硝酸纤维素膜上不迁移的特性将E2竞争物固定于检测区,巧妙解决了常规试纸对信号材料尺寸的纳米级别限制和小尺寸PLPs余辉短暂的矛盾;采用低功率紫外灯为激发光源,以智能手机实现时间分辨荧光(TRF)模式荧光采集,有效去除试纸荧光背景干扰进而提高信噪比。该时间分辨荧光侧流分析(TRF-LFA)法对E2的检出限为0.1 ng/mL,比胶体金侧流分析(CG-LFA)降低了2个数量级,且特异性良好,30 min可完成检测。将该方法应用于水中E2的检测,与HPLC-FLD法的结果一致。

A competitive time-resolved fluorescence(TRF)lateral flow assay for 17β-estradiol(E2)was established with 17β-estradiol-BSA(E2-BSA)coupled persistent luminescence particles(PLPs)as fluorescence donor and colloidal gold(CG)-labelled antibody as fluorescence receptor,based on im⁃mune recognition and fluorescence resonance energy transfer principle.In this method,the PLPs with long persistent luminescence but large size of micron were applied as the fluorescence signal source,and its non-migration property on nitrocellulose membrane was used to fix the E2 competitor in the test zone,thus the contradiction between the limitation that the signal material of traditional test paper must be nanometer size and the short luminous lifetime of small PLPs was skillfully solved.In addition,a low-power UV lamp was used as the light source to excite the PLPs,and the continuous shooting func⁃tion of smart phone was used to realize TRF-mode fluorescence acquisition,effectively removing the fluorescent background interference from the test strips and improving the signal-to-noise ratio.The de⁃tection limit of this method was 0.1 ng/mL,which was about two orders of magnitude more sensitive than those of colloidal gold and HPLC-FLD method.The detection limit of this method was 0.1 ng/mL,which was about two orders of magnitude more sensitive than that of colloidal gold.The method showed good selectivity and could perform detection in 30 min.Using this method to detect E2 in a water sam⁃ple and the results were consistent with that of HPLC-FLD method.