Fan Ruolan, Du Jiale, Park Kwang-Won, Chang Lin Hui, Strieter Eric R, Andrew Trisha L
Department of Chemistry, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States.
Department of Chemistry and Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States.
ACS Appl Polym Mater. 2021 May 14;3(5):2561-2567. doi: 10.1021/acsapm.1c00140. Epub 2021 Apr 13.
To produce next-generation, shelf-stable biosensors for point-of-care diagnostics, a combination of rugged biomolecular recognition elements, efficient encapsulants, and innocuous deposition approaches is needed. Furthermore, to ensure that the sensitivity and specificity that are inherent to biological recognition elements are maintained in solid-state biosensing systems, site-specific immobilization chemistries must be invoked such that the function of the biomolecule remains unperturbed. In this work, we present a widely applicable strategy to develop robust solid-state biosensors using emergent nanobody (Nb) recognition elements coupled with a vapor-deposited polymer encapsulation layer. As compared to conventional immunoglobulin G antibodies, Nbs are smaller (12-15 kDa as opposed to ~150 kDa), have higher thermal stability and pH tolerance, boast greater ease of recombinant production, and are capable of binding antigens with high affinity and specificity. Photoinitiated chemical vapor deposition affords thin, protective polymer barrier layers over immobilized Nb arrays that allow for retention of Nb activity and specificity after both storage under ambient conditions and complete desiccation. Most importantly, we also demonstrate that vapor-deposited polymer encapsulation of Nb arrays enables specific detection of target proteins in complex heterogeneous samples, such as unpurified cell lysate, which is otherwise challenging to achieve with bare Nb arrays.
为了生产用于即时诊断的下一代、可长期保存的生物传感器，需要将坚固的生物分子识别元件、高效的封装材料和无害的沉积方法结合起来。此外，为了确保生物识别元件固有的灵敏度和特异性在固态生物传感系统中得以保持，必须采用位点特异性固定化学方法，以使生物分子的功能不受干扰。在这项工作中，我们提出了一种广泛适用的策略，即利用新兴的纳米抗体（Nb）识别元件与气相沉积聚合物封装层相结合，来开发坚固的固态生物传感器。与传统的免疫球蛋白G抗体相比，纳米抗体更小（12 - 15 kDa，而不是约150 kDa），具有更高的热稳定性和pH耐受性，更易于重组生产，并且能够以高亲和力和特异性结合抗原。光引发化学气相沉积在固定的纳米抗体阵列上提供了薄的、保护性的聚合物阻挡层，使得在环境条件下储存和完全干燥后，纳米抗体的活性和特异性得以保留。最重要的是，我们还证明，纳米抗体阵列的气相沉积聚合物封装能够特异性检测复杂异质样品中的目标蛋白，如未纯化的细胞裂解物，而裸纳米抗体阵列很难做到这一点。
