Immunochromatographic dipstick assay format using gold manoparticles labeled protein-hapten conjugate for the detection of atrazine
Immunochromatographic dipstick assay format using gold manoparticles labeled protein-hapten conjugate for the detection of atrazine
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DOI：
10.1021/es070194j
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发表时间：
2007-07-15
影响因子：
11.4
通讯作者：
Suri, C. Raman
中科院分区：
文献类型：
--
作者：
Kaur, Jasdeep;Singh, K. Vikas;Suri, C. Raman
本研究描述了一种基于侧向流动的试纸免疫分析形式，该方法使用一种新型的半抗原-蛋白质-金偶联物来快速筛查水样中的阿特拉津。该免疫分析方法基于竞争抑制原理，即新开发的半抗原-蛋白-金结合物与样品中存在的游离抗原竞争，对于试纸条膜上有限的抗体结合部位，放置在塑料盒中。作为检测试剂的示踪剂是通过半抗原(阿特拉津的衍生物)分子与载体蛋白(牛血清白蛋白)的表面赖氨酸残基结合，然后通过载体蛋白的半胱氨酸残基将胶体金纳米颗粒连接到半抗原-蛋白结合物上而制备的。所开发的结合物表现出高水平的稳定性，因为即使在环境条件下储存8周后，它也没有表现出任何显着的活性损失。基于竞争抑制法的共轭显色与样品中阿特拉津的浓度相关。利用纳米金颗粒作为放大标签，提高了试纸的灵敏度，使标准水样中阿特拉津的检出限降至1.0 ppb。该试剂盒可作为一种快速筛查方法，在分析时间的5分钟内目视筛查水样中的阿特拉津污染，当与便携式比色仪配合使用时，可作为一种廉价的半定量分析方法。所报道的方法可用于在很短的时间内对大量农药样品进行田间筛选。
The present study describes a lateral-flow-based dipstick immunoassay format using a novel hapten-protein-gold conjugate for the rapid screening of atrazine in water samples. The immunoassay is based on the competitive inhibition, in which a newly developed hapten-protein-gold conjugate competes with the free antigen present in the sample, for the limited antibody binding sites available at test-zone on dipstick membrane, housed in a plastic cartridge The tracer used as the detection reagent was prepared by first conjugating hapten (a derivative of atrazine) molecules to a carrier protein (bovine serum albumin) via its surface lysine residues and then linking colloidal gold nanoparticles to the hapten-protein conjugate via cysteine residues of the carrier protein. The developed conjugate showed a high level of stability as it did not show any significant loss of activity even after 8 weeks of storage at ambient conditions. The color developed due to conjugate, based on competitive inhibition approach, is correlated with the concentration of atrazine sample. The sensitivity of the developed dipstick was enhanced by gold nanoparticles, as an amplification tag, presenting detection limit of atrazine in standard water samples down to 1.0 ppb level. The kit could serve as a rapid screening methodology for visual screening of atrazine contamination of water samples within 5 min of analysis time, and, when coupled with a portable colorimeter, as an inexpensive semi-quantitative assay. The method reported can be useful for screening a large number of pesticides samples in a very short time in the field.