Kim Kyeongnyeon, Han Do Kyoung, Choi Namhyun, Kim Soo Hyeon, Joung Younju, Kim Kihyun, Ho Ngoc Thanh, Joo Sang-Woo, Choo Jaebum
Department of Chemistry, Chung-Ang University, Seoul 06974, South Korea.
Division of Materials Analysis and Research, Korea Basic Science Institute, Daejeon 34133, South Korea.
Anal Chem. 2021 May 4;93(17):6673-6681. doi: 10.1021/acs.analchem.0c05336. Epub 2021 Apr 20.
The surface-enhanced Raman scattering (SERS)-based lateral flow assay (LFA) strip has been considered a high-sensitivity sensor that can overcome the low sensitivity and the difficulty of quantitative analysis problems inherent in the colorimetric LFA sensor. In the SERS-based LFA strip reported so far, a liquid sample flows through the nitrocellulose membrane in a single pathway. In some cases, however, this single-flow approach still has a limitation in detection sensitivity. This study developed a conceptually new SERS-based dual-flow LFA sensor to improve the detection sensitivity in a single-flow LFA sensor. First, a 25 nm Raman reporter-labeled gold nanoparticle (AuNP) solution flowed through one way, and a 45 nm AuNP solution continuously flowed through another path. This sequential flow of two different AuNP solutions enables forming additional bright hot spots between 25 and 45 nm AuNPs in the test line, and the SERS signal is strongly enhanced. Using this SERS-based dual-flow LFA sensor, it was possible to detect thyroid-stimulating hormone less than 0.5 μIU/mL that cannot be measured with a SERS-based single-flow LFA sensor.
基于表面增强拉曼散射（SERS）的侧向流动分析（LFA）试纸条被认为是一种高灵敏度传感器，它能够克服比色法LFA传感器固有的低灵敏度和定量分析困难的问题。在迄今为止报道的基于SERS的LFA试纸条中，液体样品以单一途径流过硝酸纤维素膜。然而，在某些情况下，这种单一流路方法在检测灵敏度方面仍然存在局限性。本研究开发了一种概念全新的基于SERS的双流LFA传感器，以提高单一流路LFA传感器的检测灵敏度。首先，一种25纳米拉曼报告分子标记的金纳米颗粒（AuNP）溶液以一种方式流过，同时一种45纳米的AuNP溶液持续从另一条路径流过。这两种不同AuNP溶液的顺序流动能够在测试线中25至45纳米的AuNP之间形成额外的明亮热点，并且SERS信号得到强烈增强。使用这种基于SERS的双流LFA传感器，能够检测到低于0.5 μIU/mL的促甲状腺激素，而这是基于SERS的单一流路LFA传感器无法测量的。
