Tungsten Disulphide Modified Interdigitated Electrochemical Sensor for Nitrite Detection

Nitrite is an industrial waste which causes lots of health-related issues when it comes in contact with humans. Thus, the detection of Nitrite is necessary. Herein, the detection of Nitrite was performed using a CO2laser ablated polyimide sensor. The sensor had an interdigitated array topology, with the working electrode being changed using the electrochemical deposition process to incorporate Tungsten Di-Sulphide (WS2). The necessary material characterization has been performed, and the performance analysis of the sensor was accomplished using Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS) using 5 mM K4[Fe (CN)6] and 1 mM KCl. The linear range of the sensor was determined to be between 0.1 and 1000 μM. The sensitivity was 0.034 μA/ (μM cm2) for concentrations ranging from 0.1 to 20 μM, and 0.004 μA/ (μM cm2) for concentrations ranging from 50 to 1000 μM. The determined Limit of Detection (LoD) was 0.083 μM, and the Limit of Quantification (LoQ) was 0.252 μM. In addition, a selectivity study was conducted, and the sensor's performance was verified using real sample analysis. In future the on-chip readout circuit will be developed so that the point of care standalone system can be enabled.