Autonomous microfluidic sensors for nutrient detection applied to nitrite, nitrate, phospate, manganese and iron

We present the design, fabrication, analysis and characterisation of autonomous high accuracy and sensitivity microfluidic nutrient sensors. A stand-alone sensor platform with integrated sub-systems is demonstrated, which is portable and capable of in-situ reagent-based nutrient analysis. The system is based on a low cost optical detection method, together with an automated microfluidic delivery system that is able to detect nitrite (e.g.) with a Limit of Detection (LOD) of 14nM. The platform was operated in-situ at Southampton Dockhead for 37 hours, performing 284 measurements.