Paper-based electrode using cellulose-polyaniline composite: Fabrication and heavy metal detection

• Main Authors: Impas, Melanie Grace W., Tan, Daisylyn Senna Y.
• Format: text
• Language: English
• Published: Animo Repository 2016
• Subjects: Heavy metals; Electrodes; Chemistry
• Online Access: https://animorepository.dlsu.edu.ph/etd_bachelors/5489
• Institution: De La Salle University

Due to industrialization and urbanization, heavy metals that are detrimental to humans are found in trace amounts almost everywhere. There is a need for a cheap and rapid detection of heavy metals. This study offers a first step into a simpler, cheaper and possibly portable way to accurately detect heavy metals in low concentrations. It aims to fabricate a paper based electrode using Polyaniline (PANI) coated cellulose and optimize its efficiency in detecting lead. The Clad-PANI composite was fabricated through the autocatalytic polymerization of polyaniline onto the surface of Cladophora cellulose using Aniline-HCI and ammonium perxodisulfate. The fabricated green composite was then characterized using fourier transform infrared spectroscopy, scanning electron microscope, energy dispersive x-ray spectroscopy and electrochemical impedance spectroscopy. The composite was turned into a working electrode using epoxy resin, copper wire and silver paste. This was tested with CV and was found to be quasi-reversible with the characteristic double peak of polyaniline. Through anodic stripping voltammetry (ASV), a calibration curve from 0.2ppm to 1.0 ppm was established. It was found that the electrode can detect at low concentrations of lead with a LOD and LOQ of 0.0721 ppm and 0.2184 ppm, respectively. The analytical sensitivity showed that the electrode is more sensitive to changes at lower concentrations of lead and is better at detecting in relatively lower concentrations. The presence of lead was detected in three separately prepared solutions and the concentration of the solution was estimated using the fabricated Clad-PANI electrode. The concentrations obtained from ASV Clad-PANI electrode were all within the acceptable 10% margin of difference from the results obtained from an atomic absorption spectroscopy. A t-test comparing the concentrations obtained from atomic absorption spectroscopy (AAS) and ASV with the Clad-PANI electrode had a high p-value of 0.6030 and had a t statistic that was much lower than its c