In-Planta Nitrate Detection Using Insertable Plant Microsensor

This paper reports a nutrient microsensor for in-situ detection of nitrate concentration inside plants. The sensor is inserted into the stalk of maize plant for continuous monitoring of dynamic nitrate uptake of the plant. The inserted part of the sensor consists of a nitrate sensing unit that works on the principle of chemical sensitive field effect transistor (chemFET), an integrated metallic thin-film thermorist, and a microscale reference electrode. The sensor enables measurement of nitrate concentration variations under different environmental conditions (e.g., light condition) and irrigation and fertigtation management. This device offers a new method to continuously detect and quantify nitrate levels inside the plants.