基于催化发卡组装信号放大技术的比率型SERS传感器用于microRNA检测及拉曼成像研究

Surface-enhanced Raman scattering (SERS) has become one of the most significant detection methods in biochemical analysis and biosensing due to its advantages including high sensitivity, high resolution, and fast analysis speed etc. However, the majority of the SERS substrates still suffer from poor stability and reproducibility, and there is no further signal amplification and it is vulnerable to interference from background fluorescence for most of the conventional SERS sensors, therefore, it is urgently need to improve the sensitivity and specificity. This project is intended to employ the new composite nanomaterial by combine with the characteristic of grapheme analogue, semiconductor nanomaterial, and metal nanoparticles, as the SERS substrate with uniform SERS hot spots and good reproducibility. The target-triggered catalytic hairpin assembly (CHA) technology does not need exogenous primers and enzymes, and can achieve simple and fast, and low-cost signal amplification detection. This project aims to develop a series of ratiometric SERS biosensors based on CHA for the detection of microRNA with high sensitivity, specificity, and reproducibility and the Raman imaging research of tumor cell. This project will provide valuable theoretical basis and new technique support for the early diagnosis and treatment of cancer, and then promoting the further application of SERS in biochemical analysis and biomedical research.

表面增强拉曼光谱（SERS）技术具有灵敏度高、分辨率高且响应快速等优点，已经成为生化分析和生物传感领域最重要的检测手段之一。然而，大部分SERS基底具有稳定性和重现性差的缺点，且传统的SERS传感器大多是基于一对一的信号转换模式，易受背景荧光干扰，灵敏度和特异性有待进一步提高。本项目将类石墨烯、半导体纳米材料和贵金属纳米颗粒的特性相结合制备新型复合纳米材料，作为SERS热点均匀、重现性好的SERS基底，结合催化发卡组装信号放大（CHA）技术无需外源引物与酶，能够实现简单快速、成本低廉的信号放大检测等优势，构建一系列灵敏度高、特异性强和重复性好的CHA技术耦合比率型SERS新型生物传感器对microRNA的分析检测和肿瘤细胞内拉曼成像研究。本项目的实施有望为癌症的早期诊断和治疗提供有价值的理论依据和新的技术支持，从而推动SERS技术在生化分析和生物医学领域中的进一步应用。

表面增强拉曼光谱（SERS）技术具有灵敏度高、分辨率高且响应快速等优点，已经成为生化分析和生物传感领域最重要的检测手段之一。然而，大部分SERS基底具有稳定性和重现性差的缺点，且传统的SERS传感器大多是基于一对一的信号转换模式，易受背景荧光干扰，灵敏度和特异性有待进一步提高。本研究工作利用贵金属纳米材料具有SERS增强效果好、SERS热点均一等优点，将银纳米颗粒（AgNPs）沉积于单晶硅片（Si）上，制备了AgNPs@Si作为重现性好、增强因子高的SERS基底。此外，本研究工作结合催化发卡组装信号放大（CHA）技术无需外源引物与酶，能够实现简单快速、成本低廉的信号放大检测等优势，构建了一系列灵敏度高、特异性强和重复性好的CHA技术耦合SERS新型生物传感器对microRNA的分析检测以及对水环境中重金属离子的检测。本项目的完成将为肿瘤的早期诊断和水环境中重金属离子污染的快速灵敏检测提供有价值的理论依据和技术支持。（1）SERS基底的制备。针对目前SERS基底存在重现性和稳定性差、制备过程复杂等问题，制备了AgNPs@Si作为SERS增强基底，该基底具有制备简单、重现性和稳定性好、SERS增强因子高等优点。（2）比率型SERS生物传感器的构建及其对肿瘤标志物microRNA的检测。利用比率型SERS传感方法灵敏度高、特异性强的优点，结合CHA技术无需外源引物与酶，能够实现快速的信号放大检测，构建了基于CHA技术的比率型SERS生物传感器，实现了肿瘤标志物microRNA的高灵敏、高选择性检测。（3）SERS传感器对水环境中铅离子（Pb2+）的检测，结合CHA技术与SERS技术的优点，构建了高灵敏SERS传感器对Pb2+的检测。