Hierarchical Porous Graphene-Iron Carbide Hybrid Derived From Functionalized Graphene-Based Metal-Organic Gel as Efficient Electrochemical Dopamine Sensor

Eleni C Vermisoglou; Petr Jakubec; Ondřej Malina; Vojtěch Kupka; Andreas Schneemann; Roland A Fischer; Radek Zbořil; Kolleboyina Jayaramulu; Michal Otyepka

doi:10.3389/fchem.2020.00544

Hierarchical Porous Graphene-Iron Carbide Hybrid Derived From Functionalized Graphene-Based Metal-Organic Gel as Efficient Electrochemical Dopamine Sensor

Front Chem. 2020 Jul 30:8:544. doi: 10.3389/fchem.2020.00544. eCollection 2020.

Authors

Affiliations

¹ Faculty of Science, Regional Centre of Advanced Technologies and Materials, Palacký University Olomouc, Olomouc, Czechia.
² Inorganic and Metal-Organic Chemistry, Department of Chemistry and Catalysis Research Centre, Technical University of Munich, Garching, Germany.
³ Lehrstuhl für Anorganische Chemie I, Technische Universität Dresden, Dresden, Germany.
⁴ Department of Chemistry, Indian Institute of Technology Jammu, Jammu, India.

Abstract

A metal-organic gel (MOG) similar in constitution to MIL-100 (Fe) but containing a lower connectivity ligand (5-aminoisophthalate) was integrated with an isophthalate functionalized graphene (IG). The IG acted as a structure-directing templating agent, which also induced conductivity of the material. The MOG@IG was pyrolyzed at 600°C to obtain MGH-600, a hybrid of Fe/Fe₃C/FeO_x enveloped by graphene. MGH-600 shows a hierarchical pore structure, with micropores of 1.1 nm and a mesopore distribution between 2 and 6 nm, and Brunauer-Emmett-Teller surface area amounts to 216 m²/g. Furthermore, the MGH-600 composite displays magnetic properties, with bulk saturation magnetization value of 130 emu/g at room temperature. The material coated on glassy carbon electrode can distinguish between molecules with the same oxidation potential, such as dopamine in presence of ascorbic acid and revealed a satisfactory limit of detection and limit of quantification (4.39 × 10^-7 and 1.33 × 10^-6 M, respectively) for the neurotransmitter dopamine.

Keywords: dopamine; gel; graphene; metal–organic gel; nanocomposite; sensing.