title: Voltammetric detection of As(III) with Porphyridium cruentum based modified carbon paste electrode biosensor.
abstract: A novel biosensor based on carbon paste electrode modified with Porphyridium cruentum biomass was developed for the determination of As(III) in contaminated water. As(III) was first biosorbed-accumulated on the electrode surface at open circuit potential and then stripped off by applying anodic scan range of -0.8 to +0.8 V using differential pulse anodic stripping voltammetric technique. The best result was obtained at pH 6.0 with 0.1M HNO3 solution as stripping medium, allowing biosorption-accumulation time of 8 min using 5% P. cruentum biomass in graphite-mineral oil paste. Linear range for As(III) detection with the modified electrode-biosensor was observed between 2.5 and 20 µg L(-1). The FTIR spectrum of P. cruentum biomass confirmed the presence of active functional groups that participate in the binding of As(III). Scanning Electron Microscopy (SEM) indulged the surface morphology of modified electrode-biosensor before and after As(III) adsorption. Similarly, Atomic Force Microscopy (AFM) showed that the average roughness of the modified electrode decreased indicating the successful incorporation of P. cruentum biomass. Efficiency of the biosensor in the presence of different interfering metal (Na(+), K(+), Ca(2+), and Mg(2+)) ions were also evaluated. The application of P. cruentum modified biosensor was successfully used for the detection of As(III) in the binary metal (Fe(3+), Mn(2+), Cd(2+), Cu(2+), Ni(2+), Hg(2+), and Pb(2+)) contaminated system. The accuracy of application of biosorption based biosensor for the detection of As(III) is as low as 2.5 µg L(-1).
authors.affiliation: Food and Biotechnology Research Centre, PCSIR Laboratories Complex, Ferozepur Road Lahore 54600, Pakistan; Institute of Chemistry, University of the Punjab, Lahore 54590, Pakistan.
authors.forename: M
authors.initials: M
authors.lastname: Zaib
authors.affiliation: Food and Biotechnology Research Centre, PCSIR Laboratories Complex, Ferozepur Road Lahore 54600, Pakistan. Electronic address: asmadr@brain.net.pk.
authors.forename: A
authors.initials: A
authors.lastname: Saeed
authors.affiliation: Department of Chemistry, School of Science and Engineering, Lahore University of Management Sciences, Lahore 54792, Pakistan.
authors.forename: I
authors.initials: I
authors.lastname: Hussain
authors.affiliation: Institute of Chemistry, University of the Punjab, Lahore 54590, Pakistan.
authors.forename: M M
authors.initials: MM
authors.lastname: Athar
authors.affiliation: Food and Biotechnology Research Centre, PCSIR Laboratories Complex, Ferozepur Road Lahore 54600, Pakistan; Centre for Applied Molecular Biology, 87-West Canal Bank Road, Thokar Niaz Baig, Lahore 53700, Pakistan.
authors.forename: M
authors.initials: M
authors.lastname: Iqbal
mesh_terms: D001151:Arsenic / Q000032:analysis* / Q000737:chemistry; D018533:Biomass; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D002244:Carbon; D055664:Electrochemical Techniques; D004566:Electrodes; D006108:Graphite; D008670:Metals / Q000032:analysis; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D008899:Mineral Oil; D044665:Porphyridium; D017550:Spectroscopy, Fourier Transform Infrared; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry
chemical_list: D008670:Metals; D014874:Water Pollutants, Chemical; D002244:Carbon; D006108:Graphite; D008899:Mineral Oil; D001151:Arsenic
keywords: As(III); FTIR; Modified carbon paste electrode; Red alga; Voltammetry