Lab-on-a-chip Sensor for In Situ Nutrient Monitoring

Abstract

Presented here is a low-cost in situ nutrient sensor based on lab-on-a-chip (LOC) technologies. A microfluidic chip with integrated check valves and a novel absorbance cell forms the backbone of the sensor. Using spectrophotometry to measure concentrations of nitrite and phosphate in liquid samples, effective limits of detection (LOD) of 30 nM and 100 nM are achieved for nitrite and phosphate respectively using a 10 mm optical path. The sensor was deployed in the Bedford Basin in Halifax, Canada for 12 hours for in situ phosphate measurement and analysis.