Plasmonic core-shell luminescent nanoparticles: A self-supporting sensing platform

等离激元核壳发光纳米粒子：自支撑传感平台

• 批准号: RGPIN-2015-06468
• 负责人: Boudreau, Denis
• 金额: $ 2.55万
• 依托单位: Université Laval
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=614171
• 关键词: Plasmonic; core; shell; luminescent; nanoparticles

The confinement of electromagnetic fields within metallic nanoparticles is at the origin of the optical phenomenon known as localized surface plasmon resonance (LSPR). This confinement is associated with large enhancements in local field intensity, which lead in turn to significant increases in the quantum yield and radiative rates of fluorescent species placed close to the metal surface. Furthermore, one can take advantage of the LSPR frequency’s dependence on the composition, geometry, size and dielectric environment of metallic nanoparticles to design optimal nanostructures able to enhance the emission intensity of fluorophores across the spectrum from UV to the near infrared (NIR).  A significant reduction of self-quenching (i.e. signal losses occurring between neighboring fluorophores) and an  enhancement of detection sensitivity and photostability can be obtained with core-shell nanoparticles composed of a nanometer-size silver core coated by multiple layers of silica. By careful control of the spacing between the core and fluorophores arranged in concentric layers, these nanostructures can be used to enhance Förster resonant energy transfer (FRET) efficiency and range between donor-acceptor pairs localized on these multilayer composite NPs. We recently demonstrated the use of these nanoprobes as plasmonic enhancers for weakly fluorescent analytes, for the quantitative detection of specific genes at the trace level and for photostable imaging of physiological ions near cellular membranes. These multilayer core-shell nanoparticles present many of the features required of an ideal self-supported sensing platform: they offer high optical detection sensitivity, excellent chemical and photophysical stability, high dispersability in water, and facile surface functionalization. Furthermore, their mobility is an asset for probing the contents of extended sample volumes in biosensing applications or for functional cell imaging work. In this research program, we will design novel multilayer core-shell fluorescent nanoarchitectures that maximize plasmonic enhancement of luminescence and FRET, investigate their photophysical characteristics, and develop them into molecular sensing nanostructures for the sensitive detection of trace amounts of genes, biomarkers, toxins, pathogens, tumor cells, etc. and other applications in the fields of analytical chemistry, materials science, plasmonics, photonics and biotechnology.

金属纳米粒子内部电磁场的限制是称为局域表面等离子体共振（LSPR）的光学现象的起源。这种限制与局部场强的大幅增强有关，从而导致放置在靠近金属表面的荧光物质的量子产率和辐射率的显着增加。此外，人们可以利用LSPR频率对金属纳米颗粒的组成、几何形状、尺寸和介电环境的依赖来设计能够增强从紫外到近红外（NIR）光谱中荧光团发射强度的最佳纳米结构。