鼻咽癌细胞组织与血液的SERS光谱研究进展

基于表面增强拉曼光谱(SERS)技术对于人体细胞组织与血液的检测和研究,SERS光谱技术能够发现正常组织与病变组织的差异性,为医学临床上实现癌症的早期诊断提供了科学依据。由于鼻咽癌不具有明显的病变特征、病灶的位置难以通过常规医学手段检测。因此利用SERS光谱技术,应用于鼻咽癌细胞组织与血液的研究,可提高鼻咽癌患者的生存率。对鼻咽癌细胞组织与血液SERS光谱分析和诊断的探索研究,有助于SERS光谱技术发展成为一种在生物医学领域中的分析检测手段,在医学临床诊断上具有潜在的应用前景。     

表面增强拉曼光谱技术在肿瘤病理中的应用

表面增强拉曼散射（Surface-enhanced Raman Scattering,SERS）技术作为鉴定生物分子种类最有力的分析工具之一,具有灵敏度高、特异性强、稳定性好及检测条件温和等优点。目前,SERS技术在肿瘤病理领域的应用尚处于起步阶段,但已显现出良好的应用前景和发展空间。该文简要介绍了SERS的机理、特性及活性基底,并对SERS技术在肿瘤病理的研究进展、局限性及潜在应用价值方面做较为全面的综述。     

SERS光谱技术在人体体液研究中的应用

SERS光谱技术具有高检测灵敏度和高特异性的优点,广泛应用于生物组织,细胞及生物分子的研究,表现出极大的应用潜力。本文首先介绍了拉曼及SERS光谱技术的原理,综述了SERS光谱技术在人体体液分析检测的研究概况,特别介绍了本课题组针对血液、精液、尿液开展的研究工作,最后简要讨论SERS光谱技术的发展前景。     

表面增强拉曼光谱在DNA检测中的应用

随着光学技术的发展,表面增强拉曼光谱(SERS)作为一种新兴的技术被逐渐应用于生物医学领域。SERS波谱作为一种振动波谱,能够反应被测物质的内部信息,具有指纹识别特征;具备高灵敏度、高效能的特点,且能实现复合样本的同时测定;带标记的SERS技术能进一步提高SERS检测的特异性。目前SERS技术已被广泛用于体内外DNA、蛋白分子的检测,为生物分子的分析检测提供了一种崭新、高效的手段。     

基于固态基底的SERS免疫检测新方法研究

目的:通过引入新型表面增强拉曼散射(SERS)检测探针(Au-DTNB-Tyr NPs)和金标银染技术,建立基于固态硅片基底的SERS免疫检测新技术。方法:羊抗人IgM-HRP作为检测抗体,在硅片基底上检测不同浓度的人IgM,HRP催化SERS检测探针沉积,利用金标银染技术增强SERS信号。结果:所建立的SERS免疫检测新方法检测人IgM的检测限为10 pg/mL,且SERS信号强度与人IgM浓度具有良好的线性关系(R2=0.993)。结论:基于硅片基底的SERS免疫检测新技术可高灵敏地定量检测人IgM,为实现固态硅片基底对多种抗原的高通量集成化检测奠定了基础。     

SERS标记方法在生化分析中的应用

表面增强拉曼散射(SERS)标记方法结合现代生物标记方法与SERS光谱技术,使吸附到金或银等贵金属表面的标记分子的拉曼信号显著增强,并将其作为标记示踪信号,具有生物兼容性好、灵敏度高、分子特征性强和快速简便等优点,已成为新颖的标记示踪技术的研究热点之一。本文综述近年来SERS标记技术应用于基因分析、蛋白质检测、微生物检测、肿瘤靶向和小分子物质的最新进展,着重介绍蛋白质和小分子物质的检测,并展望了今后的发展方向。     

拉曼光谱技术在病原菌感染诊断中的应用进展

快速准确诊断感染性疾病病原体是遏制超级细菌传播和抗生素滥用的重要防线。目前,临床病原菌感染诊断十分依赖于培养手段,导致检测周期长达数日,不但影响了患者的及时诊治,还间接导致抗生素的滥用。拉曼光谱技术是一种无损、高灵敏的分子指纹图谱检测技术,近年来在生物学领域得到广泛应用,其具有的免培养、快速、高特异性、低成本等优点为病原菌感染的诊断提供了新方案。本文阐述了拉曼光谱技术的原理和特点,综述了其在病原菌鉴定和抗菌药物敏感性试验方面的应用进展。     

利用表面增强拉曼光谱技术分析温度及pH值对H1N1亚型流感病毒增殖的影响

表面增强拉曼光谱(SERS)是一种基于纳米颗粒的拉曼光谱,可以高灵敏度地检测流感病毒等重要病原微生物,鉴定不同毒株间的差异。为了建立一种快速检测流感病毒SERS的方法,本实验利用SERS技术对流感病毒H1N1亚型不同毒株在不同温度和pH值的条件下进行了病毒毒价强弱的检测,将流感病毒样品与金纳米颗粒混合静置后用拉曼共聚焦显微镜进行激光扫描。结果显示在pH为7.2、温度为37℃的条件下3个H1N1亚型的毒株SERS检测结果显示均出现至少1个大于(或等于)3 000的峰值,该状态下病毒毒价最强,最适合病毒生长。另外,细胞生物学方法与SERS技术结果一致,检测中均表现出较好的稳定性和准确性。     

非标记表面增强拉曼光谱在DNA检测中的应用

表面增强拉曼光谱(SERS)是一种超灵敏的生化分析技术,已经被广泛运用于细胞、核酸、蛋白质等生物分子的检测,在生物医学领域表现出了巨大的应用潜力。近年来,将表面增强拉曼光谱技术应用于遗传物质DNA的精准检测,引起了人们广泛的关注。本文简要叙述了表面增强拉曼光谱技术的基本原理及其在DNA检测中的优势,主要介绍了非标记的DNA-SERS检测应用进展,其中包括本项目组的相关工作。研究表明,非标记DNA-SERS技术有望成为一种快速、准确的临床诊断方式。     

表面等离子体-拉曼散射双模式复合生物芯片

本文提出了复合表面等离子体(SPR)无标记检测及表面增强拉曼散射(SERS)的显微成像技术.证明了双模式SPR-SERS生物芯片的可实施性,即在同一芯片上实现了表面等离子共振和表面增强拉曼显微检测.鉴于双模芯片的高保真性,基于显微技术的高精准、多通道无标记检测技术有望在临床医学检测中得以广泛应用.     

Rapid and Sensitive Detection of Rotavirus Molecular Signatures Using Surface Enhanced Raman Spectroscopy

Human enteric virus infections range from gastroenteritis to life threatening diseases such as myocarditis and aseptic meningitis. Rotavirus is one of the most common enteric agents and mortality associated with infection can be very significant in developing countries. Most enteric viruses produce diseases that are not distinct from other pathogens, and current diagnostics is limited in breadth and sensitivity required to advance virus detection schemes for disease intervention strategies. A spectroscopic assay based on surface enhanced Raman scattering (SERS) has been developed for rapid and sensitive detection of rotavirus. The SERS method relies on the fabrication of silver nanorod array substrates that are extremely SERS-active allowing for direct structural characterization of viruses. SERS spectra for eight rotavirus strains were analyzed to qualitatively identify rotaviruses and to classify each according to G and P genotype and strain with >96% accuracy, and a quantitative model based on partial least squares regression analysis was evaluated. This novel SERS-based virus detection method shows that SERS can be used to identify spectral fingerprints of human rotaviruses, and suggests that this detection method can be used for pathogen detection central to human health care.     

Nanoplasmonic sensor for foodborne pathogens detection. Towards development of ISO‐SERS methodology for taxonomic affiliation of Campylobacter spp.

According to EU summary report on zoonoses, zoonotic agents and food‐borne outbreaks in 2017, Campylobacter was the most commonly reported gastrointestinal bacterial pathogen in humans in the EU. Unfortunately, the standard methods for the detection of thermotolerant Campylobacter spp. in foods are time‐consuming. Additionally, the qualified staff is obligatory. For this reason, new methods of pathogens detection are needed. The present work demonstrates that surface‐enhanced Raman scattering (SERS) is a reliable and fast method for detection of Campylobacter spp. in food samples. The proposed method combines the SERS measurements performed on an Ag/Si substrate with two initial steps of the ISO standard procedure. Finally, the principal component analysis (PCA) allows for statistical classification of the studied bacteria. By applying the proposed ISO‐SERS‐PCA method in the case of Campylobacter bacteria the total detection time may be reduced from 7 to 8 days required by ISO method to 3 to 4 days in the case of SERS‐based approach.     

Development of highly reliable SERS‐active photonic crystal fiber probe and its application in the detection of ovarian cancer biomarker in cyst fluid

Conventionally Surface‐enhanced Raman spectroscopy (SERS) is realized by adsorbing analytes onto nano‐roughened planar substrate coated with noble metals (silver or gold) or their colloidal nanoparticles (NPs). Nanoscale irregularities in such substrates/NPs could lead to SERS sensors with poor reproducibility and repeatability. Herein, we demonstrate a suspended core photonic crystal fiber (PCF) based SERS sensor with extremely high reproducibility and repeatability in measurement with a relative SD of only 1.5% and 4.6%, respectively, which makes it more reliable than any existing SERS sensor platforms. In addition, our platform could improve the detection sensitivity owing to the increased interaction area between the guided light and the analyte, which is incorporated into the holes that runs along the length of the PCF. Numerical calculation established the significance of the interplay between light coupling efficiency and evanescent field distribution, which could eventually determine the sensitivity and reliability of the developed SERS active‐PCF sensor. As a proof of concept, using this sensor, we demonstrated the detection of haptoglobin, a biomarker for ovarian cancer, contained within the ovarian cyst fluid, which facilitated in differentiating the stages of cancer. We envision that with necessary refinements, this platform could potentially be translated as a next‐generation highly sensitive SERS‐active opto‐fluidic biopsy needle for the detection of biomarkers in body fluids.     

Trace-Level Detection of Explosive Molecules with Triangular Silver Nanoplates-Based SERS Substrates

We report a simple route to design highly sensitive triangular silver nanoplates (TSNPs)-based SERS substrate for the trace-level detection of explosive molecules. The size-dependent localized surface plasmon resonance (LSPR) tunability for the synthesis of TSNPs is achieved by controlling reaction kinetics and seed volume in a modified seed-mediated approach. The computed extinction spectra of TSNP, using the finite-difference time-domain (FDTD) method, are in excellent agreement with the experimental results, therefore assisting further in the investigation of the plasmonic properties of TSNP. The higher electric field enhancement offered by TSNP is systematically investigated by performing the FDTD simulations for various sizes and corner rounding of TSNP. The FDTD results show that the dipolar plasmon resonance wavelength, size, and corner rounding of TSNP are the principal contributing factors for designing the high-performance SERS substrate. Herein, we have used a portable Raman system for the SERS-based detection of three important explosive molecules: picric acid (PA), ammonium nitrate (AN), and 2, 4-dinitrotoluene (DNT). The TSNP-based SERS substrates display excellent intensity enhancement factors of?~?10⁷ for rhodamine 6G (R6G) and PA and?~?10⁵ for AN. The high sensitivity of SERS substrate with limit-of-detection (LOD) of value 2.3?×?10^?11 M for PA and 3.1?×?10^?8 M for AN and effective batch-to-batch reproducibility for DNT, thus offering its potentials for field detection of explosive molecules at trace-level.

     

Quantitative Surface-Enhanced Raman for Gene Expression Estimation

We demonstrate for the first time, to our knowledge, a unique gene expression assay by surface-enhanced Raman scattering (SERS) using nonfluorescent Raman labels to quantify gene expression at the resolution of alternative splicing using RNA extracted from cancer cells without any amplification steps. Our approach capitalizes on the inherent plasmon-phonon mode of SERS substrates as a self-referencing standard for the detection and quantification of genetic materials. A strategy integrating S1 nuclease digestion with SERS detection was developed to quantify the expression levels of splice junction Δ(9,10), a segment of the breast cancer susceptibility gene 1 (BRCA1) from MCF-7 and MDA-MB-231 cells. Quantification results were cross-validated using two Raman tags and qualitatively confirmed by RT-PCR. Our methodology based on SERS technology provides reliable gene expression data with high sensitivity, bypassing the intricacies involved in fabricating a consistent SERS substrate.     

Novel and Sensitive Core-Shell Nanoparticles Based on Surface Plasmon Resonance

In this paper, a rough silver core-shell nanoparticle with strong electric field enhancement in the vicinity of a bumpy structure on the silver core-shell surface is reported. A dipolar plasmonic mode of the silver nanoshell is investigated by using the quasi-static approach and plasmon hybridization theory, which analytical results identify the electric field enhancement spectra in which the enhancement is optimized. As the silver shell thickness is small, the hot spots play an important role in the plasmonic field enhancement. In addition, the deposition of a rough silver shell can generate a stronger near-field enhancement near the silver surface which is more desirable than that of a smooth silver shell for sensitive detection based on SPR and surface enhanced Raman scattering (SERS). The plasmonic field enhancement of a bumpy silver core-shell nanoparticle permits the detection and characterization of bovine serum albumin (BSA) protein molecule and hemoglobin solution with a high sensitivity.     

Study on gastric cancer blood plasma based on surface-enhanced Raman spectroscopy combined with multivariate analysis

A surface-enhanced Raman spectroscopy (SERS) method combined with multivariate analysis was developed for non-invasive gastric cancer detection. SERS measurements were performed on two groups of blood plasma samples: one group from 32 gastric patients and the other group from 33 healthy volunteers. Tentative assignments of the Raman bands in the measured SERS spectra suggest interesting cancer-specific biomolecular changes, including an increase in the relative amounts of nucleic acid, collagen, phospholipids and phenylalanine and a decrease in the percentage of amino acids and saccharide in the blood plasma of gastric cancer patients as compared with those of healthy subjects. Principal components analysis (PCA) and linear discriminant analysis (LDA) were employed to develop effective diagnostic algorithms for classification of SERS spectra between normal and cancer plasma with high sensitivity (79.5%) and specificity (91%). A receiver operating characteristic (ROC) curve was employed to assess the accuracy of diagnostic algorithms based on PCA-LDA. The results from this exploratory study demonstrate that SERS plasma analysis combined with PCA-LDA has tremendous potential for the non-invasive detection of gastric cancers.