UK-Further development of droplet microfluidic based chemical sensors for rapid measurement of nutrients in water

传统上，水生环境中的化学物质（如硝酸盐、磷酸盐）是通过人工收集和实验室分析离散水样来测量的。微流体传感器提供了一个有吸引力的替代方案：通过在环境中自主采集和分析样品，它们消除了人工采样的需要，并允许实时监测水的成分和质量。由于一系列问题，目前最先进的传感器并不普遍，最明显的是复杂的流体控制和它们对化学试剂的低效使用。这增加了传感器的尺寸和功耗，限制了每次测量的频率和传感器每次可部署的持续时间。液滴微流控（将纳升水样采集，然后在不混相油中作为液滴进行操作）是一种新型的微流控方法，除了其他优点外，关键是提供更高的分析通量和更有效地使用消耗品（试剂消耗降低了几个数量级）。我们之前已经开发并展示了用于测量硝酸盐和亚硝酸盐的第一个液滴微流体传感器原型，相对于目前的技术水平，它使用的试剂消耗大大降低。在这个项目中，我们将与最终用户（包括英国公共机构和中国水务公司）合作，使技术成熟，并在实际操作中进行演示。这些演示将帮助我们改进传感器，证明其有效性，并为商业开发做好准备。

Traditionally chemicals in the aquatic environment (e.g. nitrate, phosphate) are measured by manual collection and laboratory analysis of discrete water samples. Microfluidic sensors offer an attractive alternative: by taking and analysing samples autonomously in the environment, they remove the need for manual sampling and allow real-time monitoring of water composition and quality.The current state-of-the-art sensors are not widespread due to a range of issues, most notably complicated fluidic control and their inefficient use of chemical reagent. This increases the size of the sensor and its power consumption, limits the frequency that measurements can be taken and duration the sensor can be deployed each time.Droplet microfluidics (in which nanolitre water samples are taken and subsequently operated on as droplets within an immiscible oil) is a novel microfluidic method that, in addition to other advantages, crucially offers higher analytical throughput and much more efficient use of consumables (reagent consumption being orders of magnitude lower). We have previously developed and demonstrated the first-ever droplet microfluidic sensor prototype for measuring nitrate and nitrite that uses drastically lower reagent consumption relative to the current state of the art. In this project we will mature the technology and demonstrate it in real-world operation in partnership with end users, including a UK public body and Chinese water company. These demonstrations will help us to refine the sensor, demonstrate its effectiveness, and ready it for commercial exploitation.