采用磁性纳米微球增强信号的表面等离子体共振免疫传感系统检测水中莠去津残留
Detection of atrazine residues in water by magnetic nanoparticles enhanced surface plasmon resonance immunosensor
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摘要: 将磁性纳米微球(MNP,表面修饰羧基的磁性四氧化三铁微球)与表面等离子体共振(SPR)免疫传感技术结合,以莠去津单克隆抗体(AT-mAb)与磁性纳米微球的偶联物(AT-mAb-MNP)作为传感识别元件,初步建立了一种用于饮用水中除草剂莠去津残留检测的SPR信号增强免疫传感方法。通过对检测条件的优化,该方法对自来水中莠去津的检出限为0.89 ng/mL(S/N=3),检测范围为8.62~7.18×103 ng/mL,检测时间小于20 min;在10~1000 ng/mL添加水平内,莠去津的平均回收率为94%~102%,相对标准偏差(RSD)为5.1%~7.3%。磁性纳米微球的加入有效增强了SPR传感器的响应信号强度,提高了检测方法的灵敏度。本研究建立了一种快速、灵敏、准确的水中莠去津残留的检测方法,可为相应的现场检测技术和设备的研发提供技术基础。Abstract: A signal enhanced immunosensing detection method for atrazine residue in drinking water was established. Magnetic nanoparticles(MNP) were introduced into surface plasmon resonance(SPR) sensing system for signal enhancement. The conjugate of atrazine monoclonal antibodies(AT-mAb) and MNP was used as sensing recognition element. Under the optimized conditions, the minimum detection limit of the established method reached 0.89 ng/mL(S/N=3) with analytical range of 8.62-7.18×103 ng/mL. The detection for one sample could be performed in less than 20 min. Recoveries of spiked samples were found to be between 94% and 102% with RSDs of 5.1%-7.3% at 10-1000 ng/mL. Signal intensity and detection sensitivity of the SPR sensing system were effectively enhanced comparing with that without MNP. Thus, a rapid, sensitive and accurate detection method for atrazine residue in water was established. This technique showed potential use in on-site detection technique and equipments.
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