A flow-through electrochemical sensor with renewable copper modified electrode for sensitive nitrate detection

a flow-through electrochemical sensor modified with renewable copper sensitive material for long-term nitrate measurement is demonstrated. The flow-through sensor based on conventional electrochemical electrodes was developed to implement long-term nitrate monitoring under a programmed operation protocol. The freshly deposited copper was employed as the electrocatalyst material for nitrate reduction. The corresponding cathodic amperometric values were measured to carry out nitrate determination. The renewal of copper sensing material was achieved by electrodepositing a fresh copper layer before each measurement, which is the key factor for sensitivity and reproducibility of long-term nitrate detection. The experimental results reveal that the sensor performed high sensitivity of 1.093 μA/mgL-1 for continuous nitrate determination. The linearity range for NO3- samples is from 0 to 12.1 mg L-1.