In Situ Sensing System for the Selective and Sensitive Detection of Biological Toxins in HABs

全球海洋和淡水环境中有害藻华（HABs）的频率越来越高，这是一个重大的公共卫生和环境科学问题，因为它可能释放生物毒素，特别是由蓝藻藻华产生的微囊藻毒素（MCs）。目前的监测方法采用现场采样，然后在实验室对有害藻华毒素进行分析（直接微观观察），既不可持续，也不实用，无法满足巨大的时空测量需求。另外，基于从卫星图像中识别标准颜色产品的遥感方法（间接宏观观测）对于监测一般的藻华活动是有用的。然而，这些颜色产品既不是赤潮所特有的，也不一定表明毒素释放。因此，确定藻华的有毒/无毒性质，甚至以更有效，可持续和响应的方式确定有害藻华毒素的种类是很重要的。在我们努力寻找两种不同观测方法的互补方法的过程中，本研究的总体目标是使用创新的无线传感器网络实时监测原位MCs水平。在这个项目中，德克萨斯大学阿灵顿分校、新墨西哥州立大学和弗吉尼亚理工学院的研究人员将探索：(1)监测赤潮活动期间毒素释放的新方法；(2)在痕量水平上鉴定和量化各种MCs的创新思路；(3)实现适合现场应用的传感器网络的集成方法。提出的传感系统将利用一个表面定制的光学天线来选择性和敏感地分析MCs。该天线由具有多种MCs特定换能器层的谐振纳米结构阵列组成，通过分析亚波长表面等离子体的光谱特性来检测MCs与换能器层的特定结合。将开发一个无线传感网络，在传感节点和远程当局之间通信分析数据和操作命令。执行传感协议所需的大多数组件，包括阵列芯片、光学传感器、光电探测器阵列和电路，都被集成到芯片大小的单一基板中，用于系统自动化。更广泛的影响：该项目的结果预计将对传感器网络的设计和发展以及现场环境监测领域的科学研究产生重大影响。现场实时监测方法有利于即时决策和及时反应，这是建立作为环境基础设施的预警系统的关键要素。教育影响包括学生参与项目的培训，与课程的研究整合，以及使用原位传感器网络测试平台的实践研究经验。在这个项目中开发的软件工具和模拟器将通过互联网提供给研究和教育社区。团队成员将利用参与大学现有的组织和项目，从代表性不足的群体中招募和指导学生。由NSF和NIEHS联合资助：该项目的原始提案（R01 ES021951-01）是根据资助机会公告RFA-ES-11-013，“海洋，大湖和人类健康（R01）”提交给国家环境健康科学研究所（NIH/NIEHS）的，这是一个由NSF联合赞助的机会。本项目由NSF和NIEHS分别合作资助。

The increasing frequency of harmful algal blooms (HABs) in marine and freshwater environments worldwide is a significant public health and environmental science concern because of the potential release of biological toxins -- in particular, microcystins (MCs) produced from cyanobacterial HABs. Current monitoring methods employing on-site sampling followed by in-lab analysis of HAB toxins (direct micro-observation) are neither sustainable nor practical to meet the vast spatial and temporal measuring need. Alternatively, remote sensing approaches based on identifying standard color products from satellite images (indirect macro-observation) are useful for monitoring general algal bloom activities. However, such color products are neither specific to HABs nor necessarily indicative of toxin release. As a result, it is important to determine the toxic/non-toxic nature of algal blooms and even identify the species of HAB toxins in a more effective, sustainable, and responsive manner. In our efforts to find a complementary approach to the two different observing methods, the overall goal of this proposed study is to real-time monitor the level of MCs in situ using an innovative wireless sensor network. In this project, researchers at the University of Texas at Arlington, New Mexico State University, and Virginia Polytechnic Institute will explore: (1) novel approaches to monitor toxin release during HAB activities, (2) innovative ideas to qualify and quantify various MCs at trace levels, and (3) integrated ways to realize the sensor network suitable for field applications. The proposed sensing system will utilize a surface-customized optical antenna to assay MCs selectively and sensitively. The antenna, consisting of arrays of resonant nanostructures with various transducer layers specific to multiple MCs, detects specific bindings of MCs to the transducer layers by analyzing the spectral characteristics of the subwavelength surface plasmon. A wireless sensing network to communicate assay data and operation command between sensing nodes and remote authorities will be developed. Most of the components necessary for executing the sensing protocol, including array chip, optical sensor, photo-detector array, and circuitries, are incorporated into a chip-size single substrate for system automation. Broader Impacts: Results of this project are expected to have significant impacts on the design and development of sensor networks and on scientific studies in the area of in situ environmental monitoring. The in situ real-time monitoring approach benefits immediate decision-making and timely response, which are crucial elements for establishing an early warning system as an environmental infrastructure. Educational impacts include students training by participating in the project, research integration with curricula, and hands-on research experience using the in situ sensor network testbed. Software tools and simulators developed during this project will be made available via the internet to research and education communities. Team members will take advantage of the existing organizations and programs in the participating universities to recruit and mentor students from underrepresented groups. JOINT FUNDING BY NSF AND NIEHS: The original proposal on which this project is based (R01 ES021951-01) was submitted to the National Institutes of Environmental Health Sciences (NIH/NIEHS) in response to Funding Opportunity Announcement RFA-ES-11-013 , "Oceans, Great Lakes and Human Health (R01)", an opportunity jointly sponsored by NSF. This project is cooperatively funded through separate awards from NSF and NIEHS.