School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom.
Institute for Materials Research (IMO), Hasselt University, BE-3590 Diepenbeek, Belgium.
ACS Appl Mater Interfaces. 2021 Apr 21;13(15):17353-17360. doi: 10.1021/acsami.1c02280. Epub 2021 Apr 12.
Single-domain antibodies, known as nanobodies, have great potential as biorecognition elements for sensors because of their small size, affinity, specificity, and robustness. However, facile and efficient methods of nanobody immobilization are sought that retain their maximum functionality. Herein, we describe the direct immobilization of nanobodies on gold sensors by exploiting a modified cysteine strategically positioned at the C-terminal end of the nanobody. The experimental data based on secondary ion mass spectrometry, circular dichroism, and surface plasmon resonance, taken together with a detailed computational work (molecular dynamics simulations), support the formation of stable and well-oriented nanobody monolayers. Furthermore, the nanobody structure and activity is preserved, wherein the nanobody is immobilized at a high density (approximately 1 nanobody per 13 nm). The strategy for the spontaneous nanobody self-assembly is simple and effective and possesses exceptional potential to be used in numerous sensing platforms, ranging from clinical diagnosis to environmental monitoring.
单域抗体，又称为纳米抗体，由于其体积小、亲和力高、特异性强、稳定性好，在传感器作为生物识别元件方面具有巨大的潜力。然而，人们仍在寻求简便、高效的纳米抗体固定化方法，以保持其最大的功能。本文中，我们通过利用在纳米抗体 C 末端上经过修饰的半胱氨酸，将纳米抗体直接固定在金传感器上。基于二次离子质谱、圆二色性和表面等离子体共振的实验数据，以及详细的计算工作（分子动力学模拟），共同支持了稳定且定向良好的纳米抗体单层的形成。此外，纳米抗体的结构和活性得以保留，其中纳米抗体以高密度（约每 13nm 有 1 个纳米抗体）固定。这种自发的纳米抗体自组装策略简单有效，具有在从临床诊断到环境监测等众多传感平台中应用的巨大潜力。
