基于表面增强拉曼散射(SERS)技术的细菌指纹性鉴定及杀菌机理研究

Bacterial infections seriously affect human's health. Thus, the bacteria detection and sterilization are the key points to protect human health from bacterial infection. With complex analytical procedures and time-consuming process, traditional examinations of bacterial infections were not timely. Moreover, some molecular information is still lacking because of the difficulty in in situ detecting trace information on the interactions between the antibiotic and bacteria. Benefits from the electromagnetic enhancement on the metal surface, the surface enhanced Raman scattering (SERS) can sensitively and specifically identify the chemical and biological compounds through their unique vibrational fingerprints. Therefore, the SERS is expected as an ideal technique to realize the bacteria detection and study the detailed molecular mechanism of drug sterilization. The aim of the present study is to clarify the relationship between the SERS effect and the superparticles which fabricated through experimental rectify and theoretical simulation by different building blocks of Au, Ag, and Cu. Subsequently, the obtained excellent SERS substrates are used to detect various bacteria and get their "fingerprint identification". Additionally, the in situ detection of the bacteria can be used to reveal the detailed molecular mechanism of the sterilization process for antibiotic. These results will provide important experimental and theoretical support for clinically detection of bacteria, sterilization, and developing new antibiotics.

细菌的感染严重影响着人类的健康。传统的细菌检测通常面临着检测周期长、操作复杂等问题，难以实现细菌的及时检测。另外在抗生素杀菌过程中，由于抗生素分子与细菌体的作用较弱难以通过原位检测，因此抗生素杀菌的详细信息存在缺失。受益于贵金属表面的电磁增强现象，表面增强拉曼散射(SERS)技术能够实现单分子的高灵敏、高选择性的指纹检测，因而成为细菌检测及药物杀菌中分子机理研究的理想方法。本项目中以金、银、铜等纳米粒子为主要基元，通过实验对比及理论模拟和计算，设计和制备具备优异SERS效应的纳米超粒子。利用其优异的SERS活性检测不同的细菌，建立细菌的“指纹身份证”。更进一步的利用纳米超晶格结构的SERS活性基底原位检测抗生素的杀菌过程，揭示杀菌的详细机理。这将对临床上细菌的高效检测、对菌下药及开发新抗生素提供重要的理论和实验支持。

分子信息、有机体（细菌）信息等的快速高灵敏检测，对疾病的诊断、预防、治疗等方面具有重要作用。表面增强拉曼散射(SERS)具有操作简单、灵敏度高、选择性好、样品无需预处理、检测过程无损等优势，因而成为分子、有机体（细菌）检测的理想方法。应用SERS检测时，必须满足：具有产生电磁增强的拉曼活性基底和待测样品产生拉曼信号或拉曼信号变化。本项目通过自组装制备金或银有序纳米阵列基SERS活性基底，利用该基底实现分子和细菌的指纹检测。项目研究中，首先通过优化合成参数调控制备不同形貌、尺寸均一的金或银纳米晶体；以此为自组装基元，调控制备和组装金或银有序纳米自组装体；研究纳米自组装体的SERS活性；基于该SERS活性基底对葡萄糖球菌和大肠杆菌的进行无标记特征检测；理论和实验指导进一步的探索复杂环境中拉曼散射截面小的待测物的SERS检测的应用研究。本项目研究成果，将对临床上细菌的高效检测、对菌下药、开发新抗生素以及疾病的早期诊断筛查等提供重要的理论和实验支持。