Chemistry Department of Lomonosov Moscow State University, 119991 Moscow, Russia.
Moscow Institute of Physics and Technology, Institute of Quantum Technologies, 141700 Dolgoprudny, Russia.
Biosensors (Basel). 2023 Dec 29;14(1):20. doi: 10.3390/bios14010020.
Surface-enhanced Raman spectroscopy (SERS)-based aptasensors for virus determination have attracted a lot of interest recently. This approach provides both specificity due to an aptamer component and a low limit of detection due to signal enhancement by a SERS substrate. The most successful SERS-based aptasensors have a limit of detection (LoD) of 10-100 viral particles per mL (VP/mL) that is advantageous compared to polymerase chain reactions. These characteristics of the sensors require the use of complex substrates. Previously, we described silver nanoisland SERS-substrate with a reproducible and uniform surface, demonstrating high potency for industrial production and a suboptimal LoD of 4 × 10 VP/mL of influenza A virus. Here we describe a study of the sensor morphology, revealing an unexpected mechanism of signal enhancement through the distortion of the nanoisland layer. A novel modification of the aptasensor was proposed with chromium-enhanced adhesion of silver nanoparticles to the surface as well as elimination of the buffer-dependent distortion-triggering steps. As a result, the LoD of the Influenza A virus was decreased to 190 VP/mL, placing the nanoisland SERS-based aptasensors in the rank of the most powerful sensors for viral detection.
基于表面增强拉曼光谱（SERS）的适体传感器在病毒检测方面引起了广泛关注。这种方法由于适体成分而具有特异性，并且由于 SERS 基底的信号增强而具有低检测限。最成功的基于 SERS 的适体传感器的检测限（LoD）为每毫升 10-100 个病毒颗粒（VP/mL），与聚合酶链反应相比具有优势。这些传感器的特性需要使用复杂的基底。以前，我们描述了具有可重复和均匀表面的银纳米岛 SERS 基底，展示了其用于工业生产的高潜力和不理想的流感 A 病毒 LoD 为 4×10 VP/mL。在这里，我们研究了传感器的形态，揭示了通过纳米岛层的变形增强信号的意外机制。提出了一种新型的适体传感器修饰方法，通过铬增强银纳米颗粒对表面的粘附以及消除与缓冲相关的变形触发步骤。结果，流感 A 病毒的 LoD 降低到 190 VP/mL，使基于纳米岛的 SERS 适体传感器成为用于病毒检测的最强大的传感器之一。
