Protein biomolecules are used as markers for various diseases and infections and are targets in biosensing research and development. One of the highest-sensitivity biosensing techniques is considered to be fluorescence (FL) sensing. However, to our knowledge, no study has shown that all-dielectric metasurfaces can contribute to highly sensitive FL sensing. Here, we introduce an efficient type of FL-sensing platforms and show that all-dielectric metasurface FL biosensors are able to directly detect a representative antibody, immunoglobulin G, at very small concentrations on the order of pg/mL or tens of femtomolars. Furthermore, it is shown that they work efficiently as an indirect detection platform for standard cancer marker antigens, such as carcinoembryonic antigens, at concentrations well below the medical diagnosis criterion at 5 ng/mL. Importantly, the metasurface biosensors simultaneously suppress inhomogeneous FL responses, exhibit high reproducibility, and retain sensitivity, even in human serum. These results indicate that the present metasurface FL biosensors provide a high-sensitivity practical platform, suggesting that they are a better option than the commercially standard of enzyme-linked immunosorbent assays.

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用于高灵敏度抗体/抗原检测的全介电超表面荧光生物传感器

蛋白质生物分子被用作各种疾病和感染的标志物，并且是生物传感研究和开发的目标。最高灵敏度的生物传感技术之一被认为是荧光 (FL) 传感。然而，据我们所知，没有研究表明全电介质超表面可以有助于高灵敏度的 FL 传感。在这里，我们介绍了一种有效类型的 FL 传感平台，并表明全电介质超表面 FL 生物传感器能够直接检测代表性抗体免疫球蛋白 G，其浓度非常低，约为 pg/mL 或数十飞摩尔。此外，显示它们作为标准癌症标志物抗原（例如癌胚抗原）的间接检测平台有效地工作，其浓度远低于医学诊断标准 5 ng/mL。重要的是，超表面生物传感器同时抑制不均匀的 FL 响应，表现出高重现性，并保持灵敏度，即使在人血清中也是如此。这些结果表明，目前的超表面 FL 生物传感器提供了一个高灵敏度的实用平台，表明它们是比酶联免疫吸附测定的商业标准更好的选择。