Nanoparticles (NPs) can be conjugated with diverse biomolecules and employed in biosensing to detect target analytes in biological samples. This proven concept was primarily used during the COVID-19 pandemic with gold-NP-based lateral flow assays (LFAs). Considering the gold price and its worldwide depletion, here we show that novel plasmonic NPs based on inexpensive metals, titanium nitride (TiN) and copper covered with a gold shell (Cu@Au), perform comparable to or even better than gold nanoparticles. After conjugation, these novel nanoparticles provided high figures of merit for LFA testing, such as high signals and specificity and robust naked-eye signal recognition. Since the main cost of Au NPs in commercial testing kits is the colloidal synthesis, our development with the Cu@Au and the laser-ablation-fabricated TiN NPs is exciting, offering potentially inexpensive plasmonic nanomaterials for various bioapplications. Moreover, our machine learning study showed that biodetection with TiN is more accurate than that with Au.

中文翻译：

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利用廉价金属制成的等离激元纳米颗粒进行侧向层析生物测试 — 取代胶体金


纳米颗粒 (NP) 可以与多种生物分子结合，并用于生物传感以检测生物样品中的目标分析物。这一经过验证的概念主要在 COVID-19 大流行期间使用基于金纳米粒子的侧向层析检测 (LFA)。考虑到金价及其在全球范围内的枯竭，我们在此表明​​，基于廉价金属、氮化钛（TiN）和金壳覆盖的铜（Cu@Au）的新型等离子体纳米颗粒的性能与金纳米颗粒相当甚至更好。结合后，这些新型纳米粒子为 LFA 测试提供了高品质因数，例如高信号和特异性以及强大的肉眼信号识别能力。由于商业测试套件中 Au NP 的主要成本是胶体合成，因此我们对 Cu@Au 和激光烧蚀制造的 TiN NP 的开发令人兴奋，为各种生物应用提供了潜在的廉价等离子体纳米材料。此外，我们的机器学习研究表明，TiN 生物检测比 Au 更准确。