Phosphate sensor

The NOC has developed a miniaturised phosphate sensor using microfluidic lab-on-chip (LOC) technology. This sensor allows the collection of in situ data with high spatial-temporal resolution throughout the water column (sample time ~20 minutes).

The technology uses an adapted version of the molybdate blue assay; it carries on-board standards for in situ recalibration which provides high accuracy and precision. It has a mean power consumption of 1.8W, a detection limit of 40nM, a dynamic range of 0.14–10μM, and an infield accuracy of 4 ± 4.5%.

This sensor has been deployed on pontoons and other coastal hardware, landers, a ship’s underway system, autonomous underwater vehicle, and a remote-operated vehicle.

Clinton-Bailey, G.S., Grand, M.M., Beaton, A.D., Nightingale, A.M., Owsianka, D.R., Slavik, G.J., Connelly, D.P., Cardwell, C.L., Mowlem, M.C. (2017) A Lab-on-Chip Analyzer for in Situ Measurement of Soluble Reactive Phosphate: Improved Phosphate Blue Assay and Application to Fluvial Monitoring. Environ. Sci. Technol., 51 (17), 9989–9995. https://doi.org/10.1021/acs.est.7b01581.

Grand, M.M., Clinton-Bailey, G.S., Beaton, A.D., Schaap, A.M., Johengen, T.H., Tamburri, M.N., Connelly, D.P., Mowlem, M.C., Achterberg, E.P. (2017) A Lab-On-Chip Phosphate Analyzer for Long-Term In Situ Monitoring at Fixed Observatories: Optimization and Performance Evaluation in Estuarine and Oligotrophic Coastal Waters. Front. Mar. Sci., 4. https://doi.org/10.3389/fmars.2017.00255.