Analysis and fabrication of paper based screen-printed soil potassium sensor

In this work fabrication and the COMSOL simulations of the screen-printing-based soil potassium sensor has been carried out by optimizing the dimensions of the sensor. The ionophore considered for the potassium sensing is valinomycin for which the material parameters used in the simulations have been taken from the literature. The optimized sensor dimensions and the concentrations for achieving the peak current in the cyclic voltammetry have also been reported. The three electrodes considered in the sensor are working electrode (WE), counter electrode (CE) and the reference electrode (RE). In order to optimize the sensor dimensions, the effect of WE diameter and width of CE has also been analyzed. With comprehensive simulations, the screen printing based low cost paper-based flexible sensor has been fabricated. The fabricated sensor has been characterised by collecting the soil samples of various places of the VNIT, Nagpur campus. The potassium concentrations measured in the various soil samples are in the range of 0.81 M-1.90 M with +/- 2 % tolerance. Moreover, the sensitivity of the fabricated soil sensor is found to be 101.68 mu A/M.