A droplet microfluidic-based sensor for monitoring river nitrate/nitrite concentrations

Abstract

We report a field-deployable sensor for monitoring nitrate and nitrite levels in water, based on droplet microfluidics. The sensor, a fully ruggedized development of our previously-reported prototype[1] was used in an uninterrupted three-week deployment in a tidal river where the influence of tidal variation, rain events, diurnal effects, and anthropogenic input can all be discerned. This droplet-based sensor demonstrates highly economical usage of consumables, with reagent consumption lower by approximately two orders-of-magnitude compared to the current state-of-the-art continuous-flow microfluidic sensors.[2,3].