Center for Soft and Living Matter, Institute for Basic Science (IBS), Ulsan, 44919, Republic of Korea.
Department of Biomedical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea.
Adv Mater. 2022 Jun;34(24):e2200981. doi: 10.1002/adma.202200981. Epub 2022 May 16.
Electrochemical biosensors have shown great potential for simple, fast, and cost-effective point-of-care diagnostic tools. However, direct analysis of complex biological fluids such as plasma has been limited by the loss of sensitivity caused by biofouling. By increasing the surface area, the nanostructured electrode can improve detection sensitivity. However, like a double-edged sword, a large surface area increases the nonspecific adsorption of contaminating proteins. The use of nanoporous structures may prevent fouling proteins. However, there is no straightforward approach for creating nanostructured and nanoporous surfaces compatible with microfabricated thin-film electrodes. Herein, the preferential etching of chloride and surfactant-assisted anisotropic gold reduction to create homogeneous, nanostructured, and nanoporous gold electrodes is demonstrated, yielding a 190 ± 20 times larger surface area within a minute without using templates. This process, "surfactant-based electrochemical etch-deposit interplay for nanostructure/nanopore growth" (SEEDING), on electrodes enhances the sensitivity and antibiofouling capabilities of amperometric biosensors, enabling direct analysis of tumor-derived extracellular vesicles (tEVs) in complex biofluids with a limit of detection of 300 tEVs µL from undiluted plasma and good discrimination between patients with prostate cancer from healthy ones with an area under the curve of 0.91 in urine and 0.90 in plasma samples.
电化学生物传感器在简单、快速和经济高效的即时诊断工具方面显示出巨大的潜力。然而，由于生物污垢导致的灵敏度损失，对复杂生物流体（如血浆）的直接分析受到限制。通过增加表面积，纳米结构电极可以提高检测灵敏度。然而，就像一把双刃剑，大的表面积会增加污染蛋白质的非特异性吸附。使用纳米多孔结构可以防止污垢蛋白质。然而，没有一种简单的方法可以创建与微制造的薄膜电极兼容的纳米结构和纳米多孔表面。在此，通过优先蚀刻氯化物和表面活性剂辅助的各向异性金还原来展示均匀的纳米结构和纳米多孔金电极的形成，在不使用模板的情况下，在一分钟内可获得 190±20 倍的更大表面积。这种在电极上的“基于表面活性剂的电化学刻蚀-沉积相互作用用于纳米结构/纳米孔生长”（SEEDING）过程增强了安培生物传感器的灵敏度和抗生物污垢能力，使复杂生物流体中的肿瘤衍生细胞外囊泡（tEVs）能够直接进行分析，从未稀释的血浆中检测到的 300 个 tEVs µL 的检测限，并且能够很好地区分前列腺癌患者和健康患者，在尿液和血浆样本中的曲线下面积分别为 0.91 和 0.90。
