Paper-Based Screen-Printed Electrodes: A Cost-Effective Solution for Soil Potassium Sensing

In this paper, we fabricated three electrode electrochemical sensor for the detection of potassium (K + ) in the soil. Since potassium in the soil directly impacts on the growth of the plants, it is necessary to detect the potassium. To achieve this, the low cost polyethylene terephthalate (PET) paper- based potassium sensor has been designed and fabricated by using the screen-printing technique. With the proposed fabrication setup, we have fabricated 63 sensors on A4 size PET sheet. The three electrodes in the sensor are counter electrode (CE), working electrode (WE) and the reference electrode (RE) which are analyzed by using the cyclic voltammetry. The fundamental principle of this sensor is based on the ion sensitive membrane (ISM) used on the WE. Therefore, the valinomycin is used as the ISM for sensing the K + ions. It has also been observed that, the selectivity and the sensitivity of the proposed sensor are significantly higher in comparison to the reported valinomycin based sensors. Since the proposed sensor uses the paper-based approach, the cost of each fabricated sensor is around $0.06 (₹5).