Evaluation and Adaptation of an Ion Sensitive Field Effect Transistor for Seawater pH Applications

pH值对海洋酸化和生物地球化学循环等当代化学海洋学问题具有重要意义，但在空间和时间上仍然长期采样不足。这个问题只能通过开发能够在原位稳定、长期自主运行的传感器来解决。即将到来的海洋观测时代迫切需要这种传感器，用于各种类型的拟议平台（例如系泊，剖面浮标，滑翔机）。π吗?我们建议评估用于测量海水ph的离子敏感场效应晶体管（ISFET）的性能。MBARI的初步测试表明，商用ISFET现在可能能够在海洋表面长期运行，传感器漂移最小。MBARI将对商用isfet进行并行评估。现成的isfet也将部署在海洋系泊处，以测试生物污染的影响，并确定必要的防生物污染措施。与此同时，MBARI将与现有的芯片技术合作，构建专门用于海水pH测量的ISFET传感器。在设计定制的ISFET时，将特别注意压力耐受性和参比电极的类型。广泛的影响：pH值是我们在海洋学研究中最关键的化学参数之一。目前，在获得长期的海水pH值测量方面，没有任何其他进展能像PI的工作那样成功。这一发展的好处几乎不局限于整个海洋科学界。通过这一努力改进的ISFET pH传感器技术对我们开发其他化学传感器以获得长期监测能力肯定是有价值的。此外，通过该传感器相关开发获得的经验和知识也将使工程社区在处理水系统化学的长期监测方面广泛受益。现在很难说出比海洋中的碳循环更重要的东西，而这个传感器将对理解其空间和时间变化有很大帮助。一个成功的传感器将在海洋观测系统和各种自动驾驶车辆以及基于船舶的现场项目中得到广泛应用。他们的WATCH项目将在数据分析中纳入代表性不足的群体。

pH is of fundamental importance to contemporary issues in chemical oceanography such as ocean acidification and biogeochemical cycling, yet continues to be chronically undersampled in both space and time. This problem can only be overcome through the development of sensors capable of stable, long-term autonomous operation in situ. The approaching age of ocean observatories desperately needs such sensors for the various types of proposed platforms (e.g. moorings, profiling floats, gliders). The PI?s propose to evaluate the performance of the ion sensitive field effect transistor (ISFET) for measuring seawater pH. Initial tests at MBARI indicate that commercial ISFETs may now be capable of long-term operation in the surface ocean with minimal sensor drift. A side-by-side assessment of commercially available ISFETs will be carried out at MBARI. Off-the-shelf ISFETs will also be deployed on ocean moorings to test the effects of biofouling and to determine the necessary anti-biofouling measures. Concurrent to this, MBARI will work with existing chip technologies to build an ISFET sensor specifically intended for seawater pH measurements. In designing the customized ISFET, special attention will be given to pressure tolerance and type of reference electrode. Broader Impacts: pH value is among the most critical chemical parameters to our study in oceanography. At present time, there is no any other progress as successful as PI's work in obtaining long term pH measurement in seawater. Benefit of this development is almost no limitation to entire ocean science community. The improved ISFET pH sensor technology from this effort will certainly be valuable to our development towards other chemical sensors for gaining long term monitoring ability. In addition, the experience and knowledge gained through this sensor related development will also benefit wide ranges of the engineering community in dealing with long term monitoring of chemistry in aqueous system. Its hard to name anything more important than the carbon cycle in the ocean right now, and this sensor would be a great help in understanding its spatial and temporal variability. A successful sensor would have wide application in ocean observing system and in all sorts of autonomous vehicles as well as ship-based field programs. Their WATCH program will involve under-represented groups in the data analysis.