Fabrication & Characterization of Simple Structure Self-Assembled Graphene Oxide Based Heavy Metal Ion Sensor

The simple structure and high robustness of heavy metal sensors were developed by implementing a GO/Au/FR4 Substrate configuration. In this study, the sensing characteristics of an in-house fabricated heavy-metal-ion sensor (HMS) with graphene oxide (GO) as the sensing element was presented. The HMS employed a three electrodes configuration architecture, while GO of various concentrations ranging from 0.1 to 1 mg/ml would serve as the sensing medium. The surface of the working electrode was decorated with GO through drop-casting technique. Several types of heavy metal ions such as lead (Pb), mercury (Hg), and cadmium (Cd) were used in this study. The concentration of each was prepared according to the maximum exposure limit imposed by the World Health Organization, with Pb (10 ppm), Hg (1 ppm), and Cd (5 ppm). The sensing performance was found to be proportionate to GO concentration when the sensor was exposed to 10 ppm of Pb. On selectivity test using 1 mg/ml of GO, the sensor exhibited superior sensitivity towards 10 ppm of Pb, similar to 1666.6%; followed by 5 ppm of Cd, similar to 512.8%, while 1 ppm of Hg being the least detected, similar to 10.5%. This signified GO shows greater affinity towards Pb ions detection in comparison to others.