Fabrication of Printed Circuit Board Interdigitated Electrode Sensor for Cadmium Detection

In this paper, we propose the fabrication of a novel chemiresistive (CR) interdigitated electrode (IDE) sensor using printed circuit board (PCB) technology. The CR-IDE sensor comprised a polyaniline (PANI) conductive polymer as a sensing element for cadmium (Cd(II)) ion detection in water. We investigated the complex compound formation parameters in form of resistance change caused by varying concentrations of Cd(II) ions in the presence of a PANI emeraldine base. The fabricated IDE sensors have a minimum possible gap between fingers of 100 μm with a width of 710 μm. The PANI CPs served as a practical sensing element, and the sensor’s resistance change provides information that quantifies the concentration of Cd(II) ions present in the sample. The limit of detection (LOD) of the PANI-CR IDE sensor was 1 pM (0.20132 ng), less than the WHO-permitted limit for human exposure. The sensor has performed well in a linear range of 1 pM to 1 M. Sensors can function at room temperature in real-time and potentially be analyzed in a sensitive, reliable, and cost-effective manner using the PANI conductive polymer as the CR in an IDE sensor.