title: Sensitive electrochemical sensor using a graphene-polyaniline nanocomposite for simultaneous detection of Zn(II), Cd(II), and Pb(II).
abstract: This work describes the development of an electrochemical sensor for simultaneous detection of Zn(II), Cd(II), and Pb(II) using a graphene-polyaniline (G/PANI) nanocomposite electrode prepared by reverse-phase polymerization in the presence of polyvinylpyrrolidone (PVP). Two substrate materials (plastic film and filter paper) and two nanocomposite deposition methods (drop-casting and electrospraying) were investigated. Square-wave anodic stripping voltammetry currents were higher for plastic vs. paper substrates. Performance of the G/PANI nanocomposites was characterized by scanning electron microscopy (SEM) and cyclic voltammetry. The G/PANI-modified electrode exhibited high electrochemical conductivity, producing a three-fold increase in anodic peak current (vs. the unmodified electrode). The G/PANI-modified electrode also showed evidence of increased surface area under SEM. Square-wave anodic stripping voltammetry was used to measure Zn(II), Cd(II), and Pb(II) in the presence of Bi(III). A linear working range of 1-300 μg L(-1) was established between anodic current and metal ion concentration with detection limits (S/N=3) of 1.0 μg L(-1) for Zn(II), and 0.1 μg L(-1) for both Cd(II) and Pb(II). The G/PANI-modified electrode allowed selective determination of the target metals in the presence of common metal interferences including Mn(II), Cu(II), Fe(III), Fe(II), Co(III), and Ni(II). Repeat assays on the same device demonstrated good reproducibility (%RSD<11) over 10 serial runs. Finally, this system was utilized for determining Zn(II), Cd(II), and Pb(II) in human serum using the standard addition method.
authors.affiliation: Program in Macromolecular Science, Faculty of Science, Chulalongkorn University, Phayathai Road, Patumwan, Bangkok 10330, Thailand.
authors.forename: Nipapan
authors.initials: N
authors.lastname: Ruecha
authors.affiliation: Metallurgy and Materials Science Research Institute, Chulalongkorn University, Soi Chula 12, Phayathai Road, Patumwan, Bangkok 10330, Thailand.
authors.forename: Nadnudda
authors.initials: N
authors.lastname: Rodthongkum
authors.affiliation: Department of Biomedical Engineering, Colorado State University, Fort Collins, Colorado 80523, USA.
authors.forename: David M
authors.initials: DM
authors.lastname: Cate
authors.affiliation: Department of Biomedical Engineering, Colorado State University, Fort Collins, Colorado 80523, USA; Department of Mechanical Engineering, Colorado State University, Fort Collins, Colorado 80523, USA.
authors.forename: John
authors.initials: J
authors.lastname: Volckens
authors.affiliation: Electrochemistry and Optical Spectroscopy Research Unit (EOSRU), Department of Chemistry, Faculty of Science, Chulalongkorn University, Phayathai Road, Patumwan, Bangkok 10330, Thailand; National Center of Excellence for Petroleum, Petrochemicals, Advanced Materials, Chulalongkorn University, Phayathai Road, Patumwan, Bangkok 10330, Thailand. Electronic address: orawon@chula.ac.th.
authors.forename: Orawon
authors.initials: O
authors.lastname: Chailapakul
authors.affiliation: Department of Biomedical Engineering, Colorado State University, Fort Collins, Colorado 80523, USA; Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, USA. Electronic address: chuck.henry@colostate.edu.
authors.forename: Charles S
authors.initials: CS
authors.lastname: Henry
mesh_terms: D000814:Aniline Compounds / Q000737:chemistry*; D002104:Cadmium / Q000032:analysis / Q000097:blood*; D055664:Electrochemical Techniques / Q000295:instrumentation*; D004867:Equipment Design; D006108:Graphite / Q000737:chemistry*; D006801:Humans; D007854:Lead / Q000032:analysis / Q000097:blood*; D057230:Limit of Detection; D053761:Nanocomposites / Q000737:chemistry / Q000648:ultrastructure; D015032:Zinc / Q000032:analysis / Q000097:blood*
chemical_list: D000814:Aniline Compounds; C416807:polyaniline; D002104:Cadmium; D007854:Lead; D006108:Graphite; D015032:Zinc
keywords: Diagnostic; Exposure; Heavy metal; Paper-based devices; Point-of-need; Pollution