Smart Sensors for In Situ Monitoring of Hydrothermal Vent Systems

[摘要]热液喷口系统现场监测的智能传感器。项目提交日期：2001年6月27日项目负责人：Booksh机构：亚利桑那州立大学本项目由环境生物复杂性项目、环境活动仪器开发子项目（BE-IDEA）支持。该项目的目标是开发一套5个传感器，用于对深海热液喷口内及其周围的生态系统进行原位分析。这个生态系统可能是地球上最古老的生态系统之一，对全球地球化学循环产生了长期影响，但它是最不为人所知的生态系统之一。热液喷口生态系统处于不平衡的湍流状态，热能和化学能梯度较大。沿着这个热/化学梯度，一个由管蠕虫、嗜热微生物、特殊适应的甲壳类动物和鱼类组成的复杂生态系统得以生存。我们选择了最能监测喷口生态系统的物理、化学和生物环境的传感器，以更好地了解这种独特环境与它所支持的生命之间的相互关系。原位化学传感器的发展将使热液喷口监测技术取得重大进展。我们将采用基于光纤表面等离子体共振（SPR）的传感器，集成热电偶和电导率传感器，以更好地测量热液喷口流体的密度和喷口周围海水的盐度。光纤SPR传感器可以做得足够小和敏感，以探测喷口流体/海水梯度，其中许多嗜热微生物居住。利用光纤耦合光栅光反射光谱（GLRS）传感器监测喷口流体与海水混合过程中形成的矿物沉淀物的大小分布和相对丰度。这种沉淀物形成了大多数微生物居住的排气烟囱壁。将测试光纤拉曼光谱探针，以检测可能在喷口流体中形成生物或非生物的微量有机分子。还将测试拉曼光谱，以调查火山口壁上的矿物和微生物分布。将开发一种环境压力驱动的液相色谱-拉曼光谱系统，以提高拉曼光谱对简单有机分子的选择性和灵敏度，这些有机分子可能作为食物或起源于喷口生态系统中微生物的废物。灵敏度的提高将来自新型波导技术，该技术已被证明可以将简单醇的拉曼检测极限推至低ppb。最后，一种光纤、单测量激发发射矩阵（EEM）荧光计将被用于检测和表征较大的生物分子，如氨基酸、蛋白质和DNA片段，这些生物分子可能证明在喷口生态系统中具有生物活性。每一个拟议的传感器都已经过了环境或工业过程监测的概念验证阶段。该项目将对传感器进行调整和测试，以适应更具挑战性的深海喷口监测应用。传感器代表了一项有前途的技术，满足了海洋学/极端环境下生命社区的巨大需求。如果拟议的深海研究节点海王星网络建成，这些传感器将是长期现场部署的理想选择。这些传感器的成功开发将导致技术扩展到其他生物和环境过程监测应用。

AbstractSmart Sensors for In Situ Monitoring of Hydrothermal Vent Systems.Proposal: 0119999 Date: June 27, 2001PI: Booksh Institution: Arizona State UniversityThis project is supported by the program Biocomplexity in the Environment, subprogram Instrumentation Development for Environmental Activities (BE-IDEA). The objective of this project is to develop a suite of five sensors designed for in situ analysis of the ecosystem in and around hydrothermal deep-sea vents. This ecosystem may be one of the most ancient of Earth and have had a long-term effect on global geochemical cycles, yet it is one of the least well understood. Hydrothermal vent ecosystems are in a turbulent state of disequilibrium with large gradients of thermal and chemical energy. Along this thermal/chemical gradient a complex ecosystem of tube worms, thermophilic microbes, and specially adapted crustaceans and fish survive The sensors are chosen that best monitor the physical, chemical, and biological environment of the vent ecosystem to better understand the inter-relationship between this unique environment and the life that it supports. The development of in situ chemical sensors will provide a significant advancement in the state of the art of hydrothermal vent monitoring. We will employ a fiber optic surface plasmon resonance (SPR) based sensor integrated with a thermocouple and conductivity sensor to better measure the density hydrothermal vent fluid and salinity of the seawater surrounding the vent. Fiber optic SPR sensors can be made sufficiently small and sensitive to probe the vent fluid/sea water gradient where many thermophilic microbes reside. A fiber optic coupled grating light reflectance spectroscopy (GLRS) sensor will be employed to monitor the size distribution and relative abundance of mineral precipitates that form during the mixing of vent fluid and sea water. This precipitate forms the vent chimney walls where most microbes reside. Fiber optic Raman spectroscopy probes will be tested to detect trace organic molecules that may be forming biotically or abiotically in the vent fluid. Raman spectroscopy will also be tested to survey the mineral and microbial distribution on the vent walls. An ambient pressure driven liquid chromatography-Raman spectroscopy system will be developed to enhance the selectivity and sensitivity of Raman spectroscopy to simple organic molecules that may serve as food for or originate as waste from microbes in the vent ecosystem. Sensitivity enhancement will come from novel waveguide technology that has been demonstrated to push Raman detection limits to low ppb for simple alcohols. Finally, a fiber optic, single measurement excitation-emission matrix (EEM) fluorometer will be adapted to detect and characterize larger biomolecules such as amino acids, proteins, and DNA fragments that may prove indicative of biological activity in the vent ecosystem Each of the proposed sensors has been previously developed past the proof of concept stage for environmental or industrial process monitoring. The project will adapt and test the sensors for the more challenging application of deep sea vent monitoring. The sensors represent a promising technology that fills a large need in the oceanographic/ life in extreme environments community. If the proposed NEPTUNE network of deep-sea research nodes were built, these sensors would be ideal for long-term field deployment. Successful development of these sensors would lead to expansion of the technology for other biological and environmental process monitoring applications.