China Light Industry Key Laboratory of Meat Microbial Control and Utilization, School of Food and Biological Engineering, Engineering Research Center of Bio-process, Ministry of Education, Hefei University of Technology, Hefei 230009, P. R. China.
State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, 130 Changjiang West Road, Hefei, Anhui 230036, China.
Anal Chem. 2023 Aug 22;95(33):12398-12405. doi: 10.1021/acs.analchem.3c01988. Epub 2023 Aug 9.
Surface-enhanced Raman spectroscopy (SERS) with ultrasensitive vibrational fingerprints enables quick identification and trace detection of various kinds of molecules. But proteins usually have low Raman cross sections and are difficult to generate recognizable signals in direct SERS detection. Recently, nucleic acid-peptide conjugates are emerging with great potential in structuring, assembling, catalyzing, sensing, etc., and the coupling of aptamers further enables superior biological recognition and programmability. Here, we develop the aptamer-peptide conjugates as a new kind of SERS probe for direct high-specific profiling abnormal protein levels in cancer patients. The aptamer conjugated with glutathione (GSH) functions as both the recognition element and the SERS reporters that can simultaneously generate SERS fingerprints of both peptides and nucleic acids. This kind of biocompatible probe appears to have excellent performance in high-salt environments and realizes rapid, simple, and multisignal detection of thrombin (TB). Data-driven soft independent modeling of class analogy (DD-SIMCA) is used to distinguish SERS profiles of actual blood samples and realize the identification and classification of cancer patients. Furthermore, the effect of low-temperature storage time on blood samples is analyzed by tracking the changes of SERS profiles; the results hint that plasma samples stored under 4 °C for more than 2 days could generate false negative results due to TB hydrolysis, which has important implications for clinical sample analysis. This kind of nucleic acid-peptide conjugate provides new ideas for SERS sensing strategy in the future.
表面增强拉曼光谱（SERS）具有超灵敏的振动指纹，可快速识别和痕量检测各种分子。但是，蛋白质通常具有较低的拉曼截面，并且在直接 SERS 检测中很难产生可识别的信号。最近，核酸-肽缀合物在结构、组装、催化、传感等方面具有巨大的潜力，而适配体的偶联进一步实现了优异的生物识别和可编程性。在这里，我们开发了适体-肽缀合物作为一种新的 SERS 探针，用于直接高特异性分析癌症患者异常蛋白质水平。与谷胱甘肽（GSH）偶联的适体既作为识别元件，又作为 SERS 报告分子，可以同时产生肽和核酸的 SERS 指纹。这种生物相容性探针在高盐环境中表现出优异的性能，并实现了凝血酶（TB）的快速、简单和多信号检测。基于数据驱动的软独立建模分类分析（DD-SIMCA）用于区分实际血液样本的 SERS 图谱，并实现对癌症患者的识别和分类。此外，通过跟踪 SERS 图谱的变化来分析低温储存时间对血液样本的影响；结果表明，由于 TB 水解，在 4°C 下储存超过 2 天的血浆样本可能会产生假阴性结果，这对临床样本分析具有重要意义。这种核酸-肽缀合物为未来的 SERS 传感策略提供了新的思路。
