Yin Pengkun, Peng Zhengying, Wang Qihui, Duan Yixiang, Hu Bin, Lin Qingyu
Research Center of Analytical Instrumentation, School of Mechanical Engineering, Sichuan University, Chengdu 610064, China.
State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610061, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2025 Feb 15;327:125416. doi: 10.1016/j.saa.2024.125416. Epub 2024 Nov 13.
Various surface-enhanced Raman scattering (SERS) biosensors offer powerful tools for the ultrasensitive detection of circulating tumor cells (CTCs) and tumor diagnosis. Despite their efficacy, the swift and precise preparation of SERS plasmonic nanostructures poses an ongoing challenge. In this study, we introduce DNA-assisted plasmonic nanostructures capable of producing dual signals and facilitating DNA Walker signal amplification, resulting in the development of a SERS/Fluorescent (FL) dual-mode cytosensor for CTCs detection. Firstly, Au@Ag nanoparticle multimers (Au@AgNMs) featuring interparticle nano-gaps were synthesized through DNA self-assembly and in-situ deposition, which provided plasmonic nanostructures. Hence, the nano-gap distance among Au@AgNMs was meticulously regulated after optimization to achieve both SERS enhancement and fluorescence quenching. Subsequently, the aptamer (Apt) of MUC1 recognized CTCs specifically for strand displacement reaction (SDR) and further triggered the DNA Walker reaction for signal amplification. The limit of detection (LOD) of proposed cytosensor can be obtained as low as 5 cells/mL in SERS mode and 21 cells/mL in FL mode. Hence, SERS mode confers highly precise information, while FL mode allow for rapid quantitative analysis. This dual-mode cytosensor based on plasmonic nanostructures facilitates the early detection and precise treatment of cancer or infectious diseases.
各种表面增强拉曼散射（SERS）生物传感器为循环肿瘤细胞（CTC）的超灵敏检测和肿瘤诊断提供了强大工具。尽管它们具有功效，但快速精确地制备SERS等离子体纳米结构仍然是一个持续的挑战。在本研究中，我们引入了能够产生双重信号并促进DNA步行者信号放大的DNA辅助等离子体纳米结构，从而开发出一种用于CTC检测的SERS/荧光（FL）双模细胞传感器。首先，通过DNA自组装和原位沉积合成了具有粒子间纳米间隙的金@银纳米颗粒多聚体（Au@AgNMs），这提供了等离子体纳米结构。因此，在优化后精心调节了Au@AgNMs之间的纳米间隙距离，以实现SERS增强和荧光猝灭。随后，MUC1适配体（Apt）特异性识别CTC以进行链置换反应（SDR），并进一步触发DNA步行者反应以进行信号放大。所提出的细胞传感器在SERS模式下的检测限低至5个细胞/mL，在FL模式下为21个细胞/mL。因此，SERS模式提供了高度精确的信息，而FL模式允许进行快速定量分析。这种基于等离子体纳米结构的双模细胞传感器有助于癌症或传染病的早期检测和精确治疗。
