Path to Impact for Autonomous Field Deployable Chemical Sensors: A Case Study of in Situ Nitrite Sensors

Abstract

Natural freshwater systems have been severely affected by excess loading of macronutrients (e.g., nitrogen and phosphorus) from fertilizers, fossil fuels, and human and livestock waste. In the USA, impacts to drinking water quality, biogeochemical cycles, and aquatic ecosystems are estimated to cost US$210 billion annually. Field-deployable nutrient sensors (FDS) offer potential to support research and resource management efforts by acquiring higher resolution data than are currently supported by expensive conventional sampling methods. Following nearly 40 years of research and development, FDS instruments are now starting to penetrate commercial markets. However, instrument uncertainty factors (high cost, reliability, accuracy, and precision) are key drivers impeding the uptake of FDS by the majority of users. Using nitrite sensors as a case study, we review the trends, opportunities, and challenges in producing and implementing FDS from a perspective of innovation and impact. We characterize the user community and consumer needs, identify trends in research approaches, tabulate state-of-the-art examples and specifications, and discuss data life cycle considerations. With further development of FDS through prototyping and testing in real-world applications, these tools can deliver information for protecting and restoring natural waters, enhancing process control for industrial operations and water treatment, and providing novel research insights.

Ion chromatograph with three‐dimensional printed absorbance detector for indirect ultraviolet absorbance detection of phosphate in effluent and natural waters

“…This portable analyzer has successfully been deployed within a broad range of environmental waters over long deployment periods delivering high levels of accuracy and precision [26][27][28]. Despite these high levels of analytical performance in the field, challenges arise in terms of mass manufacture of microfluidic components and assembly of LOC systems which have hampered these in-situ systems and other LOC colorimetric based systems from routine use and adoption on a mass scale [29,30].…”

Combined SPRi Sensor for Simultaneous Detection of Nitrate and Ammonium in Wastewater

“…For the continuous monitoring of nitrate in an aquatic environment, many in situ sensors have been reported [32,33]. However, these technologies have not been adopted on a large scale due to prohibitive costs [34]. Thus, simple low-cost optical detectors are being developed, such as a sensor employing a UV LED source recently designed by [35] or the above-mentioned SPR sensors.…”

Evaluation of novel Griess-reagent candidates for nitrite sensing in aqueous media identified via molecular fingerprint searching

“…4,5 Along with electrochemical, chromatographic, and capillary electrophoresis techniques, nitrite sensing applications based on optical/spectroscopic methods are the most broadly used in real-life settings. 6 Especially in environmental monitoring, wet chemistry based spectroscopic assays are routinely used and considered as goldstandard. This is due to the excellent specicity, selectivity, sensitivity and accuracy of these techniques along with their low-tech requirements, cost-efficiency, and ease-of-use.…”