Lab-on-chip technology for in situ determination of dissolved organic nutrients

这项建议解决了一个关键的技术差距：溶解的有机营养物质不能用目前的技术进行常规原位测量。尽管它们在自然环境中氮和磷酸盐的循环中很重要。这些化学物质对植物生长至关重要，并在食物链的基础上调节食物的生产。它们还可以通过高水平的直接毒性和刺激有害植物或细菌生长而成为污染物，从而导致富营养化（导致水生环境中的氧气耗尽和损害）。这些过程在广泛的水生和陆地环境中，对于环境变化的研究，以及对于自然和人为（人类介导的）过程的管理都是重要的。这包括但不限于土地使用变化、农业和水产养殖管理、土壤退化、侵蚀、城市化和废水（人类废物）管理。解决方案的潜在影响包括该技术的商业开发，以及对科学和工业应用的营养测量实践的变革性影响。最近，南安普顿在基于芯片实验室（Lab on Chip，简称LAB）技术开发用于原位测定溶解无机营养物的耐用、准确和灵敏仪器方面取得了成功，这一潜力得到了放大。有机和无机形式的技术的可用性将有助于全面和准确地评估总营养素过程。该项目将通过开发一种设备来解决这一技术差距，该设备将溶解的有机营养素（难以直接测量）转化为无机形式，可以通过我们已经开发的技术轻松测量。新技术和现有技术都将基于芯片实验室技术，该技术使用十分之一毫米尺度的通道和工程特征的制造来执行复杂的分析化学。新设备将使水样暴露于紫外线辐射和精心优化的化学条件下，将有机营养素转化为无机营养素。现有的设备通过将样品与化学品混合来测量无机营养素的浓度，该化学品发生反应并导致颜色变化。颜色变化的强度与目标营养物的浓度成正比，并使用集成到我们微流体设备中的LED和光学检测器进行电子测量。一旦这项技术概念得到证实，它将（在后续研究中）进一步发展成为淡水，地下水，河口和海洋环境的常规部署系统。该系统将被提议作为未来项目的一个重要组成部分，在下一轮的研究进行的NERC宏量营养素循环计划，专门针对流域规模监测汉普郡埃文流域。

This proposal addresses a critical technology gap: dissolved organic nutrients cannot with current technology be measured routinely in situ. This is despite their importance in the cycling of nitrogen and phosphate in the natural environment. These chemicals are essential to plant growth and regulate the production of food at the base of the food chain. They can also act as pollutants through direct toxicity at elevated levels, and by stimulation of unwanted plant or bacterial growth that can lead to eutrophication (causing oxygen depletion and damage in aquatic environments). These processes are important in a wide range of aquatic and terrestrial environments, for studies of environmental change, and for management of natural and anthropogenic (human mediated) processes. This includes but is not limited to land use change, agriculture and aquaculture management, soil impoverishment, erosion, urbanisation, and waste water (human waste) management. The potential impact of a solution includes commercial exploitation of the technology, and a transformative effect on the practice of nutrient measurement for both science and industrial applications. This potential is amplified by recent successes at Southampton in the development of robust, accurate and sensitive instrumentation for determination of dissolved inorganic nutrients in situ based on lab on chip (LOC) technology. The availability of technology for both organic and inorganic forms would enable holistic and accurate assessment of the total nutrient processes.The project will address this technology gap by developing a device that converts dissolved organic nutrients (which are difficult to measure directly) in inorganic forms that can be readily measured with technology that we have already developed. Both the new and existing technologies will be (are) based on Lab on chip technology which uses fabrication of channels and engineering features on the scale of a tenths of a millimetre to perform complex analytical chemistry. The new device will expose sample water to UV radiation and carefully optimised chemical conditions to convert organic nutrients into inorganic nutrients. The existing device measures the concentration of inorganic nutrients by mixing the sample with chemicals which react and result in a colour change. The intensity of the colour change is proportional to the concentration of the nutrient targetted and is measured electrically using LEDs and optical detectors integrated into our microfluidic device.Once this technology concept is proved it will be (in subsequent research) further developed into a routinely deployable system for freshwater, groundwater, estuaries and marine environments. This system will be proposed as an important element of a future project in the next round of research undertaken for the NERC macronutrient cycles programme specifically targeting catchment scale monitoring of the Hampshire Avon catchment.