IDBR: Development of a time-gated Raman/fluorescence micro-spectroscopy instrument for biological applications

IDBR：开发用于生物应用的时间选通拉曼/荧光显微光谱仪器

• 批准号: 0852891
• 负责人: Sebastian Wachsmann-Hogiu
• 金额: $ 50.78万
• 依托单位: University of California-Davis
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-06-15 至 2012-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0852891&HistoricalAwards=false
• 关键词: IDBR; Development; time; gated; Raman

Raman spectroscopy is the inelastic scattering of photons by molecular bonds, and therefore enables chemically-specific measurements within a sample without the use of external labels. This unique characteristic gives Raman-based techniques the potential to be used in a variety of biological research applications. However, many of the chemical components within the biological material are fluorescent, acting as a background and thus severely limiting the use of Raman spectroscopy for these applications. Although there have been attempts to reduce this background, only an optical time-gated approach can be sufficiently effective. Since the Raman signal occurs almost instantaneously with the excitation light while the fluorescence is delayed by several nanoseconds, lasers with pulses in the range of several picoseconds can be used for his purpose. A time gate that opens only for the duration of the Raman signal and closes before the background fluorescence is produced can be built by using a nonlinear medium and highpower laser pulses. This combination allows for the measurement of Raman spectra in the presence of a strong fluorescence background and opens up new potential applications of Raman spectroscopy for biological research such as (i) non-invasive characterization of the chemical composition of the endogenous fluorophores in bacteria, cells and tissues, (ii) understanding cellular processes and diseases such as cancer, vascular or neurodegenerative diseases by using natural markers, (iii) developing new probes that can be used both as fluorescence and Raman labels, (iv) noninvasive medical sensors for blood analytes such as glucose sensors for diabetes treatment. This technique will have a significant impact on related fields such as analytical chemistry, biomedicine, pharmacology, forensics, food safety, agriculture, biofuel research, environmental monitoring, and bio-defense.Outreach will involve students and educators at all levels, from middle school to postdoctoral, as well as representatives and participants from the biotechnology industry.Further information can be requested from the PI.

拉曼光谱是光子通过分子键的非弹性散射，因此能够在不使用外部标记的情况下在样品内进行化学特异性测量。这种独特的特性使基于拉曼的技术有可能用于各种生物研究应用。然而，生物材料中的许多化学成分是荧光的，作为背景，因此严重限制了拉曼光谱在这些应用中的使用。尽管已经尝试减少这种背景，但只有光学时间选通方法才足够有效。由于拉曼信号几乎与激发光同时发生，而荧光被延迟几纳秒，因此具有几皮秒范围内的脉冲的激光器可以用于该目的。通过使用非线性介质和高功率激光脉冲，可以建立仅在拉曼信号的持续时间内打开并且在背景荧光产生之前关闭的时间门。这种组合允许在强荧光背景的存在下测量拉曼光谱，并为生物研究开辟了拉曼光谱的新的潜在应用，例如（i）细菌、细胞和组织中内源荧光团的化学组成的非侵入性表征，（ii）通过使用天然标记物了解细胞过程和疾病，例如癌症、血管或神经变性疾病，（iii）开发可用作荧光和拉曼标记的新探针，（iv）用于血液分析物的非侵入性医学传感器，例如用于糖尿病治疗的葡萄糖传感器。这项技术将对相关领域产生重大影响，如分析化学、生物医学、药理学、法医学、食品安全、农业、生物燃料研究、环境监测和生物防御。外联活动将涉及从中学到博士后的各级学生和教育工作者，以及生物技术行业的代表和参与者。