Luminescent nanoparticles as trackers for imaging of flows and sensing phenomena in microchannels

荧光成像已经成为一种越来越有吸引力的检测技术，因为它是高度敏感的，以及非侵入性和非破坏性的，提供了良好的时间分辨率检测快速事件。光学成像中的挑战之一是提高空间分辨率;这将需要降低探针尺寸并结合检测单个荧光探针的能力。在这项提案中，通过跨学科的方法，我们的目标是开发新的发光纳米跟踪探针（LNt），研究这些单个颗粒在静态和流动条件下的图像，并使用LNt来解析微米级通道中的速度和浓度分布（后者使用纳米颗粒水平的传感）。LNt将通过在金和铂纳米颗粒上附着镧系元素和钌发光络合物来制备。这些颗粒将在可见光和近红外线下发光，提供不同的颜色用于检测，并且它们的图像将与每个纳米颗粒的光谱信息一起获得，这将允许颜色识别。我们将应用LNt来研究具有微米尺寸特征的流动和反应系统。这些研究将在分析小型化化学和生物系统方面提供突破，因为它们将能够以非常高的空间分辨率同时进行速度和浓度测量，这将允许亚微米尺度的现象得到解决。LNt的发光特性由颗粒所涂覆的分子标记的物理特性定义。镧系元素光发射远离光激发波长，这避免了散射光的任何干扰。红外线发射也是可能的，其对皮肤是透明的，并且对于血流，这是一个优点，因为几种血色素吸收从普通发光体发射的可见辐射。开发的纳米颗粒将用于研究复杂的亚微米级流动，这种流动可能是由于微化学单元中胺溶液中CO2吸收过程中的马兰戈尼现象而出现的。还将评估使用LNt监测血流的可行性。LNt可以量身定制用于感测不同的分子，这使它们具有感测特定化学物质的内置能力，并且独特地用于浓度和速度测量。除了镧系元素，我们还将使用钌联吡啶发光配合物，这是有吸引力的，因为它们的发光对氧的存在和氧浓度敏感。速度和浓度分布测量将被证明为使用镧系元素和钌LNt，可以分别感测小分子（芳香酸）和氧的微过程。LNt应用于流速和浓度测量的原理证明已在最近完成的授予两位首席研究员的化学和化学工程之间的学科跳跃项目中得到证明。

Fluorescence imaging has become an increasingly appealing technique for detection because it is highly sensitive as well as non-invasive and non-destructive, providing good temporal resolution for detection of fast events. One of the challenges in optical imaging is to increase spatial resolution; this would require decrease in probe size combined with the ability to detect the individual fluorescent probes. In this proposal, through an interdisciplinary approach, we aim to develop novel Luminescent Nanosized tracking probes (LNt), study the images of these single particles in static and flow conditions and use the LNt for resolving velocity and concentration profiles in micron sized channels (the latter using sensing at the nanoparticle level). The LNt will be prepared by the attachment of lanthanide and ruthenium luminescent complexes on gold and platinum nanoparticles. These particles will luminesce in the visible and near infra-red providing different colours for detection and their images will be obtained together with spectral information of each nanoparticle, which will allow colour recognition. We will apply the LNt to investigate flow and reactive systems with micron sized features. These studies will provide a breakthrough in the analysis of miniaturized chemical and biological systems because they will enable simultaneous velocity and concentration measurements with very high spatial resolution that will allow submicron scale phenomena to be resolved The luminescent properties of LNt are defined by the photophysical properties of the molecular label the particles are coated with. The lanthanide light emission is far from the light excitation wavelength, which avoids any interference of scattering light. Emission in infra red is also possible which is transparent to skin and for blood flow this is an advantage as several blood pigments absorb the visible radiation emitted from common lumophores. The nanoparticles developed will be used to investigate the complex sub-micron scale flows that can appear due to Marangoni phenomena during CO2 absorption in amine solutions in micro-chemical units. The feasibility of using the LNt to monitor blood flows will also be evaluated. LNt can be tailored-made for sensing different molecules, which gives them a built-in ability to sense specific chemical species and be uniquely used for both concentration and velocity measurements. Apart from lanthanides we will also be using ruthenium bipyridyl luminescent complexes which are attractive because their luminescence is sensitive to the presence of oxygen and oxygen concentration. Velocity and concentration profile measurements will be demonstrated for microprocesses using lanthanide and ruthenium LNt that can sense small molecules (aromatic acids) and oxygen respectively. The proof of principle of the application of LNt for flow velocity and concentration measurements had been demonstrated in a recently completed Discipline Hopping project between Chemistry and Chemical Engineering awarded to the two Principal Investigators.