title: Molybdenum disulphide and graphene quantum dots as electrode modifiers for laccase biosensor.
abstract: A nanocomposite formed from molybdenum disulphide (MoS2) and graphene quantum dots (GQDs) was proposed as a novel and suitable support for enzyme immobilisation displaying interesting electrochemical properties. The conductivity of the carbon based screen-printed electrodes was highly improved after modification with MoS2 nanoflakes and GQDs, the nanocomposite also providing compatible matrix for laccase immobilisation. The influence of different modification steps on the final electroanalytical performances of the modified electrode were evaluated by UV-vis absorption and fluorescence spectroscopy, scanning electron microscopy, transmission electron microscopy, X ray diffraction, electrochemical impedance spectroscopy and cyclic voltammetry. The developed laccase biosensor has responded efficiently to caffeic acid over a concentration range of 0.38-100µM, had a detection limit of 0.32µM and a sensitivity of 17.92nAµM(-1). The proposed analytical tool was successfully applied for the determination of total polyphenolic content from red wine samples.
authors: Centre of Bioanalysis, National Institute of Research and Development for Biological Sciences, Bucharest, 296 Splaiul Independentei, 060031 Bucharest, Romania.
authors: Ioana
authors: I
authors: Vasilescu
authors: Centre of Bioanalysis, National Institute of Research and Development for Biological Sciences, Bucharest, 296 Splaiul Independentei, 060031 Bucharest, Romania. Electronic address: sandraeremia@gmail.com.
authors: Sandra A V
authors: SA
authors: Eremia
authors: National Institute for Research and Development in Microtechnologies (IMT-Bucharest), 126A Erou Iancu Nicolae, 077190 Bucharest, Romania.
authors: Mihaela
authors: M
authors: Kusko
authors: National Institute for Research and Development in Microtechnologies (IMT-Bucharest), 126A Erou Iancu Nicolae, 077190 Bucharest, Romania. Electronic address: radoiantonio@yahoo.com.
authors: Antonio
authors: A
authors: Radoi
authors: Department of Oxide Materials and Nanomaterials, Faculty of Applied Chemistry and Material Science, University Politehnica of Bucharest, No. 1-7 Gh. Polizu Street, 011061 Bucharest, Romania.
authors: Eugeniu
authors: E
authors: Vasile
authors: Centre of Bioanalysis, National Institute of Research and Development for Biological Sciences, Bucharest, 296 Splaiul Independentei, 060031 Bucharest, Romania.
authors: Gabriel-Lucian
authors: GL
authors: Radu
mesh_terms: D015374:Biosensing Techniques; D002244:Carbon / Q000737:chemistry; D058266:Dielectric Spectroscopy; D004800:Enzymes, Immobilized / Q000737:chemistry; D006108:Graphite / Q000737:chemistry; D042845:Laccase / Q000737:chemistry*; D057230:Limit of Detection; D008982:Molybdenum / Q000737:chemistry; D059808:Polyphenols / Q000302:isolation & purification*; D045663:Quantum Dots / Q000737:chemistry*; D014920:Wine
chemical_list: D004800:Enzymes, Immobilized; D059808:Polyphenols; D002244:Carbon; D006108:Graphite; D008982:Molybdenum; D042845:Laccase
keywords: Biosensor; Graphene quantum dots; Laccase; MoS(2); Polyphenol index