title: Electrografting of thionine diazonium cation onto the graphene edges and decorating with Au nano-dendrites or glucose oxidase: Characterization and electrocatalytic applications.
abstract: Thionine (Th) diazonium cation is covalently attached onto the glassy carbon (GC) electrode via graphene nanosheets (GNs) (GC-GNs-Th). The GC-GNs-Th electrode is subjected to further modifications to fabricate (i) glucose and (ii) nitrite sensors. Further modifications include: (i) direct immobilization of glucose oxidase (GOx) and (ii) electrodeposition of gold dendrite-like nanostructures (DGNs) on the GC-GNs-Th surface, constructing GC-GNs-Th-GOx and GC-GNs-Th-DGNs modified electrodes, respectively. The GC-GNs-Th-GOx biosensor exhibited a linear response range to glucose, from 0.5 to 6.0mM, with a limit of detection (LOD) of 9.6 μM and high sensitivity of 43.2 µAcm(-2)mM(-1). Also, the GC-GNs-Th-DGNs sensor showed a wide dynamic response range for NO2(-) ion with two linear parts, from 0.05 μM to 1.0 μM and 30.0 μM to 1.0mM, a sensitivity of 263.2 μAmM(-1) and a LOD of 0.01 μM. Applicability of the modified electrodes was successfully tested by determination of glucose in human blood serum and nitrite in water based on addition/recovery tests.
authors.affiliation: Department of Chemistry, University of Isfahan, Isfahan 81746-73441, Islamic Republic of Iran. Electronic address: rkarimi@sci.ui.ac.ir.
authors.forename: Reza Karimi
authors.initials: RK
authors.lastname: Shervedani
authors.affiliation: Department of Chemistry, University of Isfahan, Isfahan 81746-73441, Islamic Republic of Iran.
authors.forename: Akbar
authors.initials: A
authors.lastname: Amini
authors.affiliation: Department of Chemistry, University of Isfahan, Isfahan 81746-73441, Islamic Republic of Iran.
authors.forename: Nima
authors.initials: N
authors.lastname: Sadeghi
mesh_terms: D001786:Blood Glucose / Q000032:analysis*; D002384:Catalysis; D002412:Cations; D003217:Conductometry / Q000295:instrumentation*; D003979:Diazonium Compounds / Q000737:chemistry*; D004595:Electroplating; D004800:Enzymes, Immobilized / Q000737:chemistry; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005949:Glucose Oxidase / Q000737:chemistry*; D006046:Gold / Q000737:chemistry; D006108:Graphite / Q000737:chemistry*; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry*; D009573:Nitrites / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D001786:Blood Glucose; D002412:Cations; D003979:Diazonium Compounds; D004800:Enzymes, Immobilized; D009573:Nitrites; D014874:Water Pollutants, Chemical; D006046:Gold; D006108:Graphite; D005949:Glucose Oxidase
keywords: Diazonium cation; Glucose oxidase; Gold-dendrite-like nanoparticles; Graphene; Thionine