Institute of Biological Information Processing (IBI-3), Bioelectronics, Forschungszentrum Jülich, 52425, Jülich, Germany.
Department of Physics "E. Pancini", University of Naples "Federico II", Via Cintia 26, 80126, Naples, Italy.
Mikrochim Acta. 2021 Feb 16;188(3):88. doi: 10.1007/s00604-021-04746-9.
A plasmon-enhanced fluorescence-based antibody-aptamer biosensor - consisting of gold nanoparticles randomly immobilized onto a glass substrate via electrostatic self-assembly - is described for specific detection of proteins in whole blood. Analyte recognition is realized through a sandwich scheme with a capture bioreceptor layer of antibodies - covalently immobilized onto the gold nanoparticle surface in upright orientation and close-packed configuration by photochemical immobilization technique (PIT) - and a top bioreceptor layer of fluorescently labelled aptamers. Such a sandwich configuration warrants not only extremely high specificity, but also an ideal fluorophore-nanostructure distance (approximately 10-15 nm) for achieving strong fluorescence amplification. For a specific application, we tested the biosensor performance in a case study for the detection of malaria-related marker Plasmodium falciparum lactate dehydrogenase (PfLDH). The proposed biosensor can specifically detect PfLDH in spiked whole blood down to 10 pM (0.3 ng/mL) without any sample pretreatment. The combination of simple and scalable fabrication, potentially high-throughput analysis, and excellent sensing performance provides a new approach to biosensing with significant advantages compared to conventional fluorescence immunoassays.
一种基于等离子体增强荧光的抗体-适体生物传感器 - 由通过静电自组装随机固定在玻璃基底上的金纳米粒子组成 - 被描述用于特异性检测全血中的蛋白质。通过三明治方案实现分析物识别，其中捕获生物受体层为抗体 - 通过光化学固定技术（PIT）以直立取向和紧密堆积的方式共价固定在金纳米粒子表面上 - 以及荧光标记适体的顶层生物受体层。这种三明治结构不仅保证了极高的特异性，而且还保证了理想的荧光团-纳米结构距离（约 10-15nm），从而实现了强荧光放大。在一个特定的应用案例中，我们测试了该生物传感器在检测疟疾相关标志物恶性疟原虫乳酸脱氢酶（PfLDH）中的性能。该生物传感器可以特异性地检测到全血中掺杂的 PfLDH，检测下限低至 10 pM（0.3ng/mL），而无需任何样品预处理。这种生物传感器具有简单且可扩展的制造、潜在的高通量分析和出色的传感性能相结合，与传统荧光免疫分析相比具有显著优势。
