AUTHOR=Yasri Nael G. , Sundramoorthy Ashok K. , Chang Woo-Jin , Gunasekaran Sundaram TITLE=Highly Selective Mercury Detection at Partially Oxidized Graphene/Poly(3,4-Ethylenedioxythiophene):Poly(Styrenesulfonate) Nanocomposite Film-Modified Electrode JOURNAL=Frontiers in Materials VOLUME=1 YEAR=2014 URL=https://www.frontiersin.org/journals/materials/articles/10.3389/fmats.2014.00033 DOI=10.3389/fmats.2014.00033 ISSN=2296-8016 ABSTRACT=

Partially oxidized graphene flakes (po-Gr) were obtained from graphite electrode by an electrochemical exfoliation method. As-produced po-Gr flakes were dispersed in water with the assistance of poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT:PSS). The po-Gr flakes and the po-Gr/PEDOT:PSS nanocomposite (po-Gr/PEDOT:PSS) were characterized by Raman spectroscopy, Fourier transform-infrared spectroscopy (FT-IR), UV–Vis spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM). In addition, we demonstrated the potential use of po-Gr/PEDOT:PSS electrode in electrochemical detection of mercury ions (Hg2+) in water samples. The presence of po-Gr sheets in PEDOT:PSS film greatly enhanced the electrochemical response for Hg2+. Cyclic voltammetry measurements showed a well-defined Hg2+ redox peaks with a cathodic peak at 0.23 V, and an anodic peak at 0.42 V. Using differential pulse stripping voltammetry, detection of Hg2+ was achieved in the range of 0.2–14 μM (R2 = 0.991), with a limit of detection of 0.19 μM for Hg2+. The electrode performed satisfactorily for sensitive and selective detection of Hg2+ in real samples, and the po-Gr/PEDOT:PSS film remains stable on the electrode surface for repeated use. Therefore, our method is potentially suitable for routine Hg2+ sensing in environmental water samples.