Low Cost Junction Sensors for Water Quality Monitoring

当需要昂贵的分析实验室工具时，在几个地点监测水质（绘图）并作为时间的函数构成了巨大的挑战。这是目前测定痕量活性化合物（PAC，如抗炎药，如扑热息痛，抗抑郁药，β-受体阻滞剂，抗生素和非法药物）的情况，这些化合物被认为是新兴的环境微污染物，但也有潜在的应用，作为水质的关键标志和药物消费的警示指标。我们最近对具有电铸微米和纳米间隙的电分析结传感器的研究表明，在低成本的即时传感和远程化学分析中，“革命”是可能的。在这个项目中，新型纳米间隙传感器将被制造和用于监测污水和水中的痕量杂质。与质谱法的比较将为真实的样品提供可靠性评估。低成本的设备，每分钟一次测量的速率将开发用于未来的分布式传感器网络的真实的时间采样的应用。这种设备在许多PAC（和其他有机微污染物）的环境监测方面具有巨大的潜力，并将导致有关环境污染的知识的显着进步。该项目将由一名博士研究员进行，主要目的是开发新的结传感器知识和在水质监测中的应用。将获得基本的化学知识和环境科学知识，并开发新的通用测量工具。将论证可行性，并开发结电极方法的能力，以期开拓未来的商业合作。主要目标是：（ii）改善结特性（间隙尺寸、表面粗糙度、材料、几何形状等）; (iii)为了利用在结工艺期间存在的短寿命中间体（寿命低至约100 μ m），在10 nm间隙系统中为30 ns）;（iv）在调制器-传感器模式中采用结电极（其中一个或多个“调制器”电极产生反应性中间体，例如氢氧化物或其它反应性中间体，以辅助“传感器”电极处的灵敏检测）;（v）提供具有远程操作的低成本传感器装置。该项目的目的是24小时运作，每分钟进行一次测量;（vi）根据测量环境中痕量有机微污染物所需的既定分析标准验证该装置;（vii）比较新开发的传感器与配备Q-TOF的LC-MS系统在灵敏度和选择性方面的性能，以准确测量质量;和（viii）在埃文河和当地污水处理厂进行短期监测计划，使用遥感和LC-MS仪器，以验证其在真实的时间情景中的性能。

Monitoring water quality in several locations (mapping) and as a function of time poses a huge challenge when expensive analytical laboratory tools are required. This is currently the case for the determination of trace levels of pharmacologically active compounds (PACs, e.g. anti-inflammatory drugs such as paracetamol, antidepressants, beta-blockers, antibiotics and illicit drugs) which are recognised as emerging environmental micropollutants but also have potential applications as key markers for water quality and tell-tale indicators for drug consumption. Our recent studies on electro-analytical junction sensors with electro-formed micro- and nanogaps suggest that a 'revolution' is possible in low cost instant sensing and remote chemical analysis. In this project novel nanogap sensors will be fabricated and employed for monitoring trace impurities in sewage and water. Comparison with mass spectroscopy will provide an assessment of reliability for real samples. Low cost devices with a rate of one measurement per minute will be developed for future application in distributed sensor networks for real time sampling. Such devices have huge potential for environmental monitoring of many PACs (and other organic micropollutants) and will result in a significant advance in knowledge concerning environmental pollution. The project will be carried out by a PhD researcher with the main aim of developing new junction sensor knowledge and applications in water quality monitoring. Fundamental chemical knowledge and environmental science knowledge will be obtained and new versatile measurement tools developed. Feasibility will be demonstrated and the power of the junction electrode approach developed with the view to exploit future commercial cooperation. Key objectives are: (i) to make novel and highly sensitive sensor devices; (ii) to improve junction characteristics (gap size, surface roughness, materials, geometry, etc.); (iii) to exploit the presence of short lived intermediates during junction processes (with life times down to ca. 30 ns in 10 nm gap systems); (iv) to employ junction electrodes in modulator-sensor mode (where one or more 'modulator' electrodes generate reactive intermediates such as hydroxide or other reactive intermediates to assist the sensitive detection at the 'sensor' electrode); (v) to provide a low cost sensor device with remote operation. The project target is a 24 hour operation with one measurement per minute; (vi) to validate the device according to set analytical standards required for measurement of trace levels of organic micropollutants in the environment; (vii) to compare the performance of newly developed sensor in terms of its sensitivity and selectivity with LC-MS system equipped with Q-TOF for accurate mass measurement; and (viii) to undertake a short monitoring program in the River Avon and a local wastewater treatment plant with the usage of both remote sensing and LC-MS instrumentation in order to verify their performance in real time scenarios.