Electrophoretic Approach for the Simultaneous Deposition and Functionalization of Reduced Graphene Oxide Nanosheets with Diazonium Compounds: Application for Lysozyme Sensing in Serum.
Electrophoretic deposition (EPD) of reduced graphene oxide nanosheets (rGO) offers several advantages over other surface coating approaches, including process simplicity, uniformity of the deposited films, and good control of the film thickness. The EPD conditions might also be of interest for the reduction of diazonium salts, which upon the release of N2molecules and generation of radicals, can form covalent bonds with the sp2hybridized carbon lattice atoms of rGO films. In this work, we report on the coating of gold electrodes in one step with rGO/polyethylenimine (PEI) thin films and their simultaneous modification using different phenyl (Ph) diazonium salt precursors bearing various functionalities such as -B(OH)2, -COOH, and -C≡CH. We show further the interest of such interfaces for designing highly sensitive sensing platforms. Azide-terminated lysozyme aptamers were clicked onto the rGO/PEI/Ph-alkynyl matrix and used for the sensing of lysozyme levels in patients suffering from inflammatory bowel disease (IBD), where lysozyme levels are up-regulated. The approach attained the required demand for the determination of lysozyme level in patients suffering from IBD with a 200 fM detection limit and a linear range up to 20 pM without signal amplification.
Univ. Lille, CNRS, Centrale Lille, ISEN, Univ. Valenciennes, UMR 8520-IEMN , F-59000 Lille, France.|Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education), Shandong University , Jinan 250061, China.
Qian
Q
Wang
International Center of Biodynamics , 1B Intrarea Portocalelor, Sector 6, 060101, Bucharest, Romania.
Alina
A
Vasilescu
Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education), Shandong University , Jinan 250061, China.
Qi
http://orcid.org/0000-0001-6518-8444
Q
Wang
Univ. Lille, CNRS, Centrale Lille, ISEN, Univ. Valenciennes, UMR 8520-IEMN , F-59000 Lille, France.
Yannick
Y
Coffinier
Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education), Shandong University , Jinan 250061, China.
Musen
M
Li
Univ. Lille, CNRS, Centrale Lille, ISEN, Univ. Valenciennes, UMR 8520-IEMN , F-59000 Lille, France.
Rabah
http://orcid.org/0000-0002-9795-9888
R
Boukherroub
Univ. Lille, CNRS, Centrale Lille, ISEN, Univ. Valenciennes, UMR 8520-IEMN , F-59000 Lille, France.
Sabine
http://orcid.org/0000-0002-1567-4943
S
Szunerits
Diazonium salts; Electrophoretic deposition; Lysozyme sensing; Reduced graphene oxide; Serum samples