CADMIUM DETECTION BY POLYANILINE-ZINC OXIDE COMPOSITE THIN-FILM SENSOR

Abstract

The conventional analytical techniques for detection of cadmium (Cd) requires expensive
equipment and skilled operators. Although sensor technology developed nowadays are
miniature and user-friendly, most of them are high in fabrication costing and complex in
preparing its sensing material. As such, composite of polyaniline (PANI) and zinc oxide (ZnO)
are selected to fabricate a simpler thin-film sensor with lower costing for Cd detection. Cd
concentration is varied in the range from 1 ppm to 100 ppm are used to analyze the sensitivity
of the sensor, and the result shows that a higher Cd concentration leads to a higher voltage
reading, in the range of 18.16 mV to 65.10 mV. This is attributed to the mechanism of Cd2+
ions adsorption on the surface of ZnO, which induces a change in conductivity. Besides, PANI
functions as a conducting polymer that stabilizes ZnO to enhance the detection performance.