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

荧光成像由于其高灵敏度、非侵入性和非破坏性，为快速事件的检测提供了良好的时间分辨率，已成为一种越来越有吸引力的检测技术。光学成像面临的挑战之一是提高空间分辨率；这将需要减少探针尺寸并结合检测单个荧光探针的能力。在本提案中，通过跨学科的方法，我们的目标是开发新型发光纳米跟踪探针（LNt），研究这些单颗粒在静态和流动条件下的图像，并使用LNt来解析微米尺寸通道中的速度和浓度分布（后者使用纳米颗粒级别的传感）。将镧系和钌的发光配合物附着在金和铂纳米颗粒上制备镧系发光纳米管。这些粒子将在可见光和近红外线中发光，提供不同的颜色供检测，它们的图像将与每个纳米粒子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。这些研究将为小型化化学和生物系统的分析提供一个突破，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，从而可以解决亚微米尺度的现象。LNt的发光特性是由涂覆在颗粒上的分子标记的光物理特性定义的。镧系光发射远离光激发波长，避免了散射光的干扰。发射红外线也是可能的，它对皮肤是透明的，对于血液流动来说，这是一个优势，因为几种血液色素吸收了普通荧光团发出的可见辐射。所开发的纳米颗粒将用于研究微化学装置中胺溶液吸收二氧化碳过程中由于马兰戈尼现象而出现的复杂亚微米尺度流动。还将评估使用LNt监测血流的可行性。LNt可以为感应不同的分子而量身定制，这使它们具有感应特定化学物质的内置能力，并且可以独特地用于浓度和速度测量。除了镧系元素外，我们还将使用联吡啶钌发光配合物，这种配合物很有吸引力，因为它们的发光对氧的存在和氧浓度很敏感。速度和浓度分布测量将演示使用镧系元素和钌LNt的微过程，它们可以分别感知小分子（芳香酸）和氧。LNt应用于流速和浓度测量的原理证明已在最近完成的化学和化学工程之间的学科跳跃项目中得到证明，该项目授予两位首席研究员。

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.