Yeung Sing Yee, Mucha Annabell, Deshmukh Ravindra, Boutrus Malak, Arnebrant Thomas, Sellergren Börje
Department of Biomedical Sciences and Biofilms-Research Center for Biointerfaces (BRCB), Faculty of Health and Society, Malmö University, 20506 Malmö, Sweden.
Faculty of Chemistry, Technical University of Dortmund, Dortmund, 44227 Germany.
ACS Cent Sci. 2017 Nov 22;3(11):1198-1207. doi: 10.1021/acscentsci.7b00412. Epub 2017 Nov 10.
We report on the design of pH-switchable monolayers allowing a reversible and ordered introduction of affinity reagents on sensor surfaces. The principal layer building blocks consist of α-(4-amidinophenoxy)alkanes decorated at the ω-position with affinity ligands. These spontaneously self-assemble on top of carboxylic acid terminated SAMs to form reversible homo or mixed monolayers (rSAMs) that are tunable with respect to the nature of the head group, layer order and stability while featuring pH responsiveness and the dynamic nature of noncovalent build assemblies. We show that this results in a range of unique biosensor features. As a first example a sialic acid rSAM featuring strong lectin affinity is here used to sense hemagglutinin and influenza virus (H5N1) at the pM and fM level by in situ ellipsometry in a fully reversible fashion. We believe that the rSAM concept will find widespread use in surface chemistry and overall for boosting sensitivity in affinity biosensors.
我们报道了一种pH可切换单分子层的设计，该设计允许在传感器表面可逆且有序地引入亲和试剂。主要的层构建模块由在ω位用亲和配体修饰的α-(4-脒基苯氧基)烷烃组成。这些分子会自发地在羧酸封端的自组装单分子层（SAMs）顶部自组装，形成可逆的同型或混合单分子层（rSAMs），其头部基团的性质、层序和稳定性均可调，同时具有pH响应性和非共价构建组装体的动态特性。我们表明，这导致了一系列独特的生物传感器特性。作为第一个例子，这里使用具有强凝集素亲和力的唾液酸rSAM，通过原位椭偏仪以完全可逆方式在皮摩尔和飞摩尔水平检测血凝素和甲型流感病毒（H5N1）。我们相信，rSAM概念将在表面化学中广泛应用，并总体上提高亲和生物传感器的灵敏度。
