A novel 3D-CB/HEC-CH@Cu hybrid electrode for sensitive and rapid ammonia nitrogen detection in environmental water

Abstract

In this paper, a sensor based on 3D-printed carbon black (3D-CB), and coated with a hydroxyethylcellulose/chitosan (HEC/CH) bilayer and finished by copper electrodeposition, is presented for the electrochemical sensing of ammonia nitrogen (AN) in water. Measurements were performed using square-wave voltammetry (SWV) in borate buffer (pH 9) under optimized conditions. The electrochemical method displayed good linear relationship between 0.7-20.4 mg/L of AN with limits of detection (LOD) and quantitation (LOQ) of 0.014 and 0.043 mg/L respectively, good precision (RSD ≤ ≃4.18% intra/inter-day, n=10), and practical throughput (~70 analyses h⁻¹). Accuracy in real waters was evaluated standard-addition and spike-recovery experiments, yielding ~99.8% recoveries. Statistical analysis was used to compare the obtained results to the expected values and no significant difference was observed between added and found concentrations. Therefore, the proposed 3D-CB/HEC–CH@Cu SWV method presents a viable alternative for the e cient, low-cost and safe determination of ammoniacal nitrogen in the water quality control process.