Project 4 Advanced Approaches to Quantifying Exposure to Heavy Metals

环境/工程：项目4.量化重金属暴露的先进方法 项目摘要 北伯明翰历史上和正在进行的空气、水和土壤污染导致区域污染 重金属和其他有毒化合物，对附近地区的健康构成高风险。分析技术 对于重金属(HM)的检测对于了解HM所致肺损伤的机制和 污染的机械和化学修复效率。目前大多数HM的分析技术 电感耦合等离子体质谱(ICP-MS)和原子吸收等检测 分光光度分析(AAS)不便于携带，需要大量样品(电感耦合等离子体质谱仪)，但并不总是足够 灵敏、缓慢，需要先进的样品制备程序。 我们的假设是，一种新型的Femto-Libs(激光诱导击穿光谱)/ LEAFS(激光激发原子荧光光谱)与中红外频率梳“光学” Nose“系统将实现对Cd、Mn、As和相关生物标记物的超灵敏和快速检测 暴露在这些金属中。 LIBS是一种基于对激光发射光谱的分析的快速、实时的分析技术 感应火花。该方法能够快速、灵敏地对任何类型的物质(固体、液体或 气体)，无需样品制备。使用纳秒激光脉冲的LIBS的检测极限通常为PPM 给HMS的。使用具有飞秒(FS)持续时间的激光脉冲(f-LIBS)激发可提供显著的 检测下限的提高。我们小组最近展示了飞秒激光器开发的突破性进展 对掺铬的ZnS/Se晶体的研究表明，这些体系具有几个基本的优点 FS激光光谱学应用。这些激光器将为两个f-LIBS平台(散装和 显微镜样品)。对于需要ppb/ppt灵敏度的应用，我们将结合f-libs平台 Leafs能够实现类似于我们团队早些时候开发的原型的卓越灵敏度(亚ppt)。 我们的目标还将是将当前的可见光-近红外频率梳技术扩展到分子 “指纹”中红外光谱范围。即将开发的光学鼻子平台将基于双梳子 基于我们在飞秒光谱方面的最新突破，在中红外波段发射飞秒振子的傅里叶变换光谱 激光及其频率下转换。该计划包括开发2-20μm频率梳 在Cr：ZNS/Se飞秒激光器及其脉冲内差频产生的基础上，利用ZnGeP2，Gase， 和/或取向图案化带隙非线性晶体。该计划中的仪器将提供实时的总配置文件 复杂混合气体中痕量气体的含量，并将提供给其他项目的传感建议 与HM接触有关的生物标志物。

Environmental/Engineering: Project #4. Advanced approaches to quantifying exposure to heavy metals Project Summary Historic and ongoing air, water, and soil pollution in North Birmingham results in area contamination with heavy metals and other toxic compounds and poses high health risk in the neighborhood. Analytical techniques for heavy metal (HM) detection are essential for understanding mechanisms of HM induced lung injury and efficiency of mechanical and chemical remediation of pollution. Majority of current analytical techniques for HM detection such as Inductively Coupled Plasma - Mass Spectrometry (ICP-MS) and Atomic Absorption Spectrophotometry (AAS) are not portable, require large amount of sample (ICP-MS), not always sufficiently sensitive, slow, and require advanced procedures for sample preparation. Our hypothesis is that development of a novel femto-LIBS (laser induced breakdown spectroscopy)/ LEAFS (laser excited atomic fluorescence spectroscopy) and middle infrared frequency comb “Optical Nose” systems will enable ultrasensitive and rapid detection of Cd, Mn, As, and biomarkers associated with exposure to these metals. LIBS is a rapid, real-time analytical technique based on the analysis of the spectral emission from laser induced sparks. The method enables fast and sensitive chemical analysis of any kind of matter (solid, liquid or gas) without sample preparation. Detection limits for LIBS using nanosecond laser pulses are typically in ppms for HMs. Excitation using laser pulses with femtosecond (fs) duration (f-LIBS) may provide significant improvement in detection limit. Our group recently demonstrated breakthrough in development of fs lasers based on chromium doped ZnS/Se crystals and showed that these systems feature several essential advantages for fs laser spectroscopy applications. These lasers will be a foundation for two f-LIBS platforms (for bulk and microscopic samples). For the applications where ppb/ppt sensitivity is required we will combine f-LIBS platform with LEAFS enabling superior sensitivity (sub-ppt) similar to prototypes developed earlier by our group. Our objective will be also to extend current visible-near IR frequency-comb techniques to molecules “fingerprint” mid-IR spectral range. This optical nose platform to be developed will be based on a dual-comb Fourier-transform spectroscopy with fs oscillators emitting in the mid-IR based on our recent breakthrough in fs lasers and their frequency down-conversion. The plan includes the development of 2-20 μm frequency combs on the basis of Cr:ZnS/Se fs laser and its intra-pulse difference frequency generation using ZnGeP2, GaSe, and/or orientation patterned GaP nonlinear crystals. This planned instrument will provide a real time total profile of the trace gas contents in complex gas mixtures and will be offered to other projects of the proposal for sensing biomarkers associated with HM exposure.