Institute of Physical and Theoretical Chemistry (IPTC), Eberhard Karls Universität Tübingen, Auf der Morgenstelle 18, 72076, Tübingen, Germany.
Institute of Microtechnology, Technische Universität Braunschweig, Alte Salzdahlumer Straße 203, 38124, Braunschweig, Germany.
Mikrochim Acta. 2023 Jan 20;190(2):62. doi: 10.1007/s00604-023-05637-x.
Antibody gold nanoparticle conjugates as recognition elements are essential for the overall performance of lateral flow assays. When immobilizing antibodies on gold nanoparticles, the challenge is to prevent aggregation and to ensure that the antibodies are correctly oriented so that they remain functional and their paratopes remain accessible. There are many methods available, and it is difficult to decide which one to use. To help selecting the most appropriate conjugate production method, different synthetic routes of binding antibodies to gold nanoparticles are systematically investigated for the purpose of a quantitative lateral flow test for small molecules. The direct comparison of different conjugate syntheses shows how to select a suitable conjugate for a lateral flow assay. The syntheses examined are direct adsorption of antibody, direct adsorption of reduced antibody, covalent binding to polyethylene glycol linker, and binding via biotin-streptavidin interaction. The conjugates are characterized using UV-Vis spectroscopy and dynamic light scattering to determine their stability. Their performance on structured lateral flow test strips is examined using calibrations for different amitriptyline concentrations. It was shown that the best conjugate for quantification of amitriptyline was realized by direct adsorption of an UV-light irradiated antibody to gold nanoparticles. The methods employed can serve as a guide for selecting the most appropriate conjugate for an application and enhance the performance of lateral flow assays.
抗体金纳米粒子缀合物作为识别元件对于侧向流动分析的整体性能至关重要。在将抗体固定在金纳米粒子上时，面临的挑战是防止聚集并确保抗体正确定向，以使它们保持功能并且其变构部位仍然可及。有许多可用的方法，很难决定使用哪种方法。为了帮助选择最合适的缀合物生产方法，系统地研究了将抗体结合到金纳米粒子上的不同合成途径，目的是进行小分子的定量侧向流动测试。不同缀合物合成的直接比较表明如何为侧向流动分析选择合适的缀合物。检查的合成方法是抗体的直接吸附、还原抗体的直接吸附、与聚乙二醇接头的共价结合以及通过生物素-链霉亲和素相互作用的结合。使用紫外-可见光谱和动态光散射法对这些缀合物进行了表征，以确定它们的稳定性。使用不同阿米替林浓度的校准来检查它们在结构型侧向流动测试条上的性能。结果表明，通过将经紫外线照射的抗体直接吸附到金纳米粒子上来实现阿米替林定量的最佳缀合物。所采用的方法可以作为选择最适合应用的缀合物的指南，并提高侧向流动分析的性能。
