Near-Infrared Fluorescent Graphene Nanomaterials for Detection of Trace Analytes

在化学测量和成像项目的支持下，以及化学系化学结构、动力学和机制B项目的共同资助下，北达科他州大学的Julia Zhao博士和她的团队正在设计一种基于石墨烯的纳米材料的化学成像新方法。 当用适当波长的光照射时，这些材料在电磁光谱的近红外（NIR）区域中发出荧光。 这提供了较低的背景信号（因此更高的灵敏度）和更深的渗透比传统的成像剂。这反过来又使生物和其他生物的内部结构成像成为可能，在环境科学，生物学和国家安全等领域具有重要的潜在应用。赵博士正在努力让北达科他州的部落学院和大学参与这项工作和更广泛的工作。 一个关键的目标是鼓励来自这个代表性不足的群体的学生考虑将科学作为一种职业选择。该项目的技术目标有三个方面：1）综合。开发一系列石墨烯基近红外荧光（NIRF）纳米材料，用于痕量分析物（特别是生物样品）的灵敏检测和成像。这些NIRF纳米材料的显著特征是：a）强荧光信号，B）可调谐荧光波长，c）高水溶性，和d）大表面积。为了实现这一目标，PI正在开发新的方法来制造具有各种尺寸和还原水平的石墨烯基NIRF纳米材料，以微调荧光波长和强度。2)基础研究。研究石墨烯材料的几何，成分和尺寸对其荧光特性的影响，包括荧光量子产率，寿命和波长。3)应用程序. NIRF纳米材料在生物分析和生物成像中的应用。NIR区域有利于低背景信号和更深的辐射穿透。使用NIRF纳米材料可以实现高灵敏度的检测和体外/体内成像。目标特性包括高量子产率、激发和发射波长的可调谐性、最小的光漂白以及激发和发射带之间的最小重叠。

With support from the Chemical Measurement and Imaging Program and co-funding from the Chemical Structure, Dynamics and Mechanisms-B Program in the Division of Chemistry, Dr. Julia Zhao and her group at the University of North Dakota are devising a new approach to chemical imaging based on graphene-based nanomaterials. When illuminated with light of the proper wavelength, these materials fluoresce in the near infrared (NIR) region of the electromagnetic spectrum. This offers lower background signals (and therefore higher sensitivity) and deeper penetration than conventional imaging agents. This in turns enables imaging the inner structures of biological and other, with important potential applications in areas such as environmental science, biology, and national security. Dr. Zhao is reaching out to engage Tribal Colleges and Universities in North Dakota both in this work and more generally. A key aim is to encourage students from this underrepresented group to consider science as a career option. The technical objectives of this project are three-fold: 1) Synthesis. The development of a series of graphene-based near-infrared fluorescent (NIRF) nanomaterials for sensitive detection and imaging of trace analytes (especially in biosamples). The distinct features of these NIRF nanomaterials are: a) intense fluorescence signals, b) tunable fluorescence wavelengths, c) high water solubility, and d) large surface area. To achieve this goal, the PI is developing new methods for making graphene-based NIRF nanomaterials with various dimensions and reduction levels to fine-tune the fluorescence wavelengths and intensities. 2) Fundamental study. Study of the geometric, compositional, and dimensional effects of graphene materials on their fluorescence properties, including fluorescence quantum yield, lifetime and wavelengths. 3) Application. The implementation of the NIRF nanomaterials in bioanalysis and bioimaging. The NIR region favors low background signals and deeper penetration of radiation. Highly sensitive detection and in vitro/vivo imaging can be accomplished using NIRF nanomaterials. Targeted properties include high quantum yield, tunability of excitation and emission wavelengths, minimal photo-bleaching, and minimal overlap between excitation and emission bands.