Department of Chemical and Biological Engineering, Drexel University, Philadelphia, PA 19104, USA.
Environ Sci Technol. 2011 Feb 15;45(4):1490-6. doi: 10.1021/es1020795. Epub 2010 Dec 28.
Microcystin-leucine-arginine (MCLR) is one of the toxic microcystin congeners produced by the common cyanobacteria, blue-green algae. A piezoelectric-excited millimeter-sized cantilever (PEMC) sensor was developed for the sensitive detection of MCLR in a flow format using both monoclonal and polyclonal antibodies that bind specifically to MCLR. PEMC is a resonant cantilever sensor whose resonant frequency decreases as target analyte binds to its surface. Monoclonal antibody against MCLR was immobilized on the sensor surface via amine coupling. As the toxin in the sample water bound to the antibody, resonant frequency decreased proportional to toxin concentration. Three water matrices, namely buffer, tap water, and river water, were spiked with MCLR standards and were successfully detected in the dynamic range of 1 pg/mL to 100 ng/mL (effective concentration -250 fg/mL to 25 ng/mL). The sensor response was characterized by a log-linear relationship between resonant frequency change and MCLR concentration. Positive verification of MCLR detection was confirmed by a sandwich binding on the sensor with a second antibody binding to MCLR on the sensor (attached in first detection step) which caused a further resonant frequency decrease. We show for the first time that MCLR in various water samples can be detected at 1 pg/mL.
微囊藻氨酸-亮氨酸-精氨酸（MCLR）是由常见蓝藻产生的毒性微囊藻同系物之一。我们开发了一种基于压电激励的毫米级悬臂梁（PEMC）传感器，用于在流动模式下使用特异性结合 MCLR 的单克隆和多克隆抗体对 MCLR 进行灵敏检测。PEMC 是一种共振悬臂梁传感器，其共振频率会随着目标分析物与其表面结合而降低。针对 MCLR 的单克隆抗体通过胺偶联固定在传感器表面。随着水样中的毒素与抗体结合，共振频率会按比例降低与毒素浓度。我们用 MCLR 标准品对缓冲液、自来水和河水这三种水基质进行了加标，在 1 pg/mL 至 100 ng/mL 的动态范围内（有效浓度为 -250 fg/mL 至 25 ng/mL）成功进行了检测。传感器响应的特征是共振频率变化与 MCLR 浓度之间存在对数线性关系。通过在传感器上进行二次抗体的夹心结合（与在第一个检测步骤中附着在传感器上的 MCLR 结合），证实了 MCLR 检测的阳性结果，这导致了进一步的共振频率降低。我们首次证明可以在 1 pg/mL 的浓度下检测各种水样中的 MCLR。
