Bioengineering Program, Northeastern University, Boston, United States.
Environ Sci Technol. 2012 Mar 20;46(6):3288-94. doi: 10.1021/es203624w. Epub 2012 Mar 7.
Required routine monitoring of endocrine disrupting compounds (EDCs) in water samples, as posed by EPA Unregulated Contaminant Regulation (UCMR3), demands for cost-effective, reliable and sensitive EDC detection methods. This study reports a reusable evanescent wave aptamer-based biosensor for rapid, sensitive and highly selective detection of 17β-estradiol, an EDC that is frequently detected in environmental water samples. In this system, the capture molecular, β-estradiol 6-(O-carboxy-methyl)oxime-BSA, was covalently immobilized onto the optical fiber sensor surface. With an indirect competitive detection mode, samples containing different concentrations of 17β-estradiol were premixed with a given concentration of fluorescence-labeled DNA aptamer, which highly specifically binds to 17β-estradiol. Then, the sample mixture is pumped to the sensor surface, and a higher concentration of 17β-estradiol leads to less fluorescence-labeled DNA aptamer bound to the sensor surface and thus to lower fluorescence signal. The dose-response curve of 17β-estradiol was established and a detection limit was determined as 2.1 nM (0.6 ng mL(-1)). The high specificity and selectivity of the sensor were demonstrated by evaluating its response to a number of potentially interfering EDCs. Potential interference of real environmental sample matrix was assessed by spiked samples in several tertiary wastewater effluents. The sensor can be regenerated with a 0.5% SDS solution (pH 1.9) over tens of times without significant deterioration of the sensor performance. This portable sensor system can be potentially applied for on-site real-time inexpensive and easy-to-use monitoring of 17β-estradiol in environmental samples such as effluents or water bodies.
环保署（EPA）非管制污染物法规（UCMR3）要求对水样中的内分泌干扰化合物（EDC）进行常规监测，因此需要经济高效、可靠且灵敏的 EDC 检测方法。本研究报告了一种可重复使用的瞬逝波适体基生物传感器，用于快速、灵敏和高度选择性地检测环境水样中经常检测到的 EDC 17β-雌二醇。在该系统中，将捕获分子β-雌二醇 6-（O-羧甲基）肟-BSA 通过共价键固定在光纤传感器表面。采用间接竞争检测模式，将含有不同浓度 17β-雌二醇的样品与给定浓度的荧光标记 DNA 适体预混合，该适体高度特异性地与 17β-雌二醇结合。然后，将样品混合物泵送到传感器表面，较高浓度的 17β-雌二醇导致与传感器表面结合的荧光标记 DNA 适体减少，从而降低荧光信号。建立了 17β-雌二醇的剂量-反应曲线，并确定检测限为 2.1 nM（0.6 ng mL(-1)）。通过评估传感器对多种潜在干扰 EDC 的响应，证明了传感器具有高特异性和选择性。通过在几种三级废水处理厂中的加标样品评估了实际环境样品基质的潜在干扰。该传感器可以用 0.5% SDS 溶液（pH 1.9）再生数十次，而不会显著降低传感器性能。这种便携式传感器系统可潜在地应用于现场实时、廉价且易于使用的环境样品（如废水或水体）中 17β-雌二醇的监测。
