Fe3O4 magnetic nanoparticles/reduced graphene oxide nanosheets as a novel electrochemical and bioeletrochemical sensing platform

Abstract

We have developed Fe3O4 magnetic nanoparticles/reduced graphene oxide nanosheets modified glassy carbon (Fe3O4/r-GO/GC) electrode as a novel system for the preparation of electrochemical sensing platform. Decorating Fe3O4 nanoparticles on graphene sheets was performed via a facile one-step chemical reaction strategy, where the reduction of GO and the in-situ generation of Fe3O4 nanoparticles occurred simultaneously. Characterization of as-made nanocomposite using X-ray diffraction (XRD), transmission electron microscopy (TEM) and alternative gradient force magnetometry (AGFM) clearly demonstrate the successful attachment of monodisperse Fe3O4 nanoparticles to graphene sheets. Electrochemical studies revealed that the Fe3O4/r-GO/GC electrode possess excellent electrocatalytic activities toward the low potential oxidation of NADH (0.05 V vs. Ag/AgCl) as well as the catalytic reduction of O2 and H2O2 at reduced overpotentials. Via immobilization of lactate dehydrogenase (LDH) as a model dehydrogenase enzyme onto the Fe3O4/r-GO/GC electrode surface, the ability of modified electrode for biosensing lactate was demonstrated. In addition, using differential pulse voltammetry (DPV) to investigate the electrochemical oxidation behavior of ascorbic acid (AA), dopamine (DA) and uric acid (UA) at Fe3O4/r-GO/GC electrode, the high electrocatalytic activity of the modified electrode toward simultaneous detection of these compounds was indicated. Finally, based on the strong electrocatalytic action of Fe3O4/r-GO/GC electrode toward both oxidation and reduction of nitrite, a sensitive amperometric sensor for nitrite determination was proposed. The Fe3O4/r-GO hybrid presented here showing favorable electrochemical features may hold great promise to the development of electrochemical sensors, molecular bioelectronic devices, biosensors and biofuel cells.

Application of graphene oxide/lanthanum-modified carbon paste electrode for the selective determination of dopamine

“…Thus, the selective determination of DA continues to challenge researchers. Now, a number of materials, such as metal complexes [12], nanoparticles [13], organics [14], and self-assembled molecular films [15], have been utilized as modifiers to fabricate highly selective DA sensors and solve problems associated with their use.…”

An electrochemical biosensor based on DNA tetrahedron/graphene composite film for highly sensitive detection of NADH

“…As seen from Fig.3C, the lower detection limit of NADH by the composite film-modified electrode was reduced down to 1 fM, with a 10 pM upper limit. Compared to the detection limit of the graphene/nanostructures combined material mentioned above, such as graphene-Au nanorods nanocomposites (6.0 μM) (Li et al, 2013b), Fe 3 O 4 magnetic nanoparticles/reduced graphene oxide nanosheets (0.4 μM) (Teymourian et al, 2013) and electroreduced graphene oxide-polythionine nanocomposite film (0.1 μM) (Li et al, 2013c), the graphene-DNA tetrahedron-gold nanoparticle modified gold disk electrode exhibited a much lower detection limit of NADH.…”

“…Shan et al modified a GCE with ionic liquidfunctionalized graphene (IL-graphene) to decrease the oxidation potential of NADH to 0.33 V (Shan et al, 2010). With the assistance Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/bios of Fe 3 O 4 magnetic nanoparticles/reduced graphene oxide nanosheets, the oxidation potential of NADH was even decreased to 0.05 V (Teymourian et al, 2013). Therefore, it is noted that graphene fragments of excellent electric conductivity may be helpful to decrease the oxidation potential of NADH (Shao et al, 2010).…”

Вплив зовнішнього магнітного поля на структуроутворення та транспортні властивості полімерних композитів на основі епоксидного полімеру та Fe3O4

“…Одним із найперспективніших функціональних наповнювачів є магнетит (Fe3O4) завдяки його унікальним магніточутливим та електропровідним властивостям [12,13]. Завдяки наявності унікальних специфічних взаємодій між магнетитом і вуглецем останніми роками великий інтерес викликали гібридні матеріали, які містять комплекси Fe3O4-карбонанотрубки (КНТ) [14], Fe3O4 -графен [15], Fe3O4 -окис графену [16][17][18][19][20][21] для використання в якості електрохімічних та біосенсорів [17], біомаркерів [18] як аноди в літій-іонних батареях [19], матеріали, які поглинають електромагнітне випромінювання [20,21].…”