title: Thermal Annealing Effect on Structural, Morphological, and Sensor Performance of PANI-Ag-Fe Based Electrochemical E. coli Sensor for Environmental Monitoring.
abstract: PANI-Ag-Fe nanocomposite thin films based electrochemical E. coli sensor was developed with thermal annealing. PANI-Ag-Fe nanocomposite thin films were prepared by oxidative polymerization of aniline and the reduction process of Ag-Fe bimetallic compound with the presence of nitric acid and PVA. The films were deposited on glass substrate using spin-coating technique before they were annealed at 300 °C. The films were characterized using XRD, UV-Vis spectroscopy, and FESEM to study the structural and morphological properties. The electrochemical sensor performance was conducted using I-V measurement electrochemical impedance spectroscopy (EIS). The sensitivity upon the presence of E. coli was measured in clean water and E. coli solution. From XRD analysis, the crystallite sizes were found to become larger for the samples after annealing. UV-Vis absorption bands for samples before and after annealing show maximum absorbance peaks at around 422 nm-424 nm and 426 nm-464 nm, respectively. FESEM images show the diameter size for nanospherical Ag-Fe alloy particles increases after annealing. The sensor performance of PANI-Ag-Fe nanocomposite thin films upon E. coli cells in liquid medium indicates the sensitivity increases after annealing.
authors.affiliation: Department of Electrical, Electronic and System Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia.
authors.forename: Norshafadzila
authors.identifier: 0000-0002-3164-2271
authors.initials: N
authors.lastname: Mohammad Naim
authors.affiliation: Department of Electrical, Electronic and System Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia.
authors.forename: H
authors.initials: H
authors.lastname: Abdullah
authors.affiliation: School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia.
authors.forename: Akrajas Ali
authors.initials: AA
authors.lastname: Umar
authors.affiliation: School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia.
authors.forename: Aidil
authors.initials: A
authors.lastname: Abdul Hamid
authors.affiliation: Institute of Microengineering and Nanoelectronics, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia.
authors.forename: Sahbudin
authors.initials: S
authors.lastname: Shaari
mesh_terms: D015374:Biosensing Techniques; D058266:Dielectric Spectroscopy; D055664:Electrochemical Techniques; D004784:Environmental Monitoring / Q000379:methods*; D004926:Escherichia coli / Q000737:chemistry* / Q000502:physiology*; D007501:Iron / Q000737:chemistry*; D053761:Nanocomposites / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D012834:Silver; D007501:Iron