Label-free ultra-sensitive detection of atrazine based on nanomechanics
Label-free ultra-sensitive detection of atrazine based on nanomechanics
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DOI：
10.1088/0957-4484/19/23/235502
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发表时间：
2008-06-11
期刊：
影响因子：
3.5
通讯作者：
Shekhawat, Gajendra S.
中科院分区：
文献类型：
--
作者：
Suri, C. Raman;Kaur, Jasdeep;Shekhawat, Gajendra S.
农田和饮用水中阿特拉津等危险农药的数量惊人地增加，这推动了新技术的发展，以检测远低于其威胁水平的这些毒素。最近阐明的微悬臂纳米机械弯曲响应于化学和生物分子的相互作用，增加了另一个重要方面的生化工程研究，并促进了发展的各种信号检测范式，在微米和nanoscale.我们报告的无标记检测的高度特异性阿特拉津抗体抗原相互作用在纳米尺度上的微悬臂，具有1 ppt（过去每万亿次）灵敏度。化学相互作用引起的悬臂梁的偏转反映了悬臂梁的应变能增加和反应的自由能减少之间的相互作用，提供了一个独特的系统，用于研究纳米力学和化学之间的连接的抗体-抗原相互作用在皮摩尔浓度与纳米分辨率。用高度特异性和定点抗阿特拉津抗体使悬臂梁功能化，并在静态和流动条件下暴露于浓度从4.65 pM到46.5 μ M的不同序列的宽范围内的靶抗原。阿特拉津与特异性抗体的抗体-抗原相互作用导致悬臂梁的净负偏转。结果表明，高特异性和抗体定点固定导致阿特拉津的超高灵敏度检测。该测量在几分钟内提供皮摩尔水平的结果，并表现出高的靶特异性。这使该技术成为验证有机毒素及其进展的快速方法。
The alarming increase in the amount of dangerous pesticides such as atrazine in agricultural fields and drinking water is driving the growth of new technologies to detect these toxins well below their threat level. The recent elucidation of microcantilever nanomechanical bending in response to chemical and biomolecular interactions has added another significant facet to biochemical engineering research and has fostered the development of a variety of signal detection paradigms, at both the microscale and the nanoscale.We report the label-free detection of highly specific atrazine antibody-antigen interactions at the nanometer scale on microcantilevers, with 1 ppt (past per trillion) sensitivity. The chemical interaction-induced deflection of the cantilever beam reflects the interplay between the strain energy increase of the cantilever and the free energy reduction of the reaction, providing a unique system for investigating the connection between the nanomechanics and the chemistry of antibody-antigen interaction at picomolar concentration with nanometer resolution. Cantilevers were functionalized with highly specific and site-directed anti-atrazine antibodies and exposed to target antigen over a wide range of concentration from 4.65 pM to 46.5 mu M of varying sequence in static and flow conditions. Antibody-antigen interaction of atrazine with the specific antibody resulted in net negative deflection of the cantilever. The results show that high specificity and site-directed antibody immobilization lead to ultra-high sensitivity detection of atrazine. The measurements provide results within minutes at the picomolar level, and exhibit high target specificity. This qualifies the technology as a rapid method to validate organic toxins and its progression.