One-pot synthesis of magnetite nanorods/graphene composites and its catalytic activity toward electrochemical detection of dopamine

• Published in: Biosensors & bioelectronics 2015-02, Vol.64, p.269-276
• Main Authors: Salamon, J., Sathishkumar, Y., Ramachandran, K., Lee, Yang Soo, Yoo, Dong Jin, Kim, Ae Rhan, Gnana kumar, G.
• Format: Article
• Language: English
• Subjects: Active sites; Anodizing; Catalysis; Conductometry - instrumentation; Crystallization; Dopamine; Dopamine - analysis; Dopamine - chemistry; Electrooxidation; Equipment Design; Equipment Failure Analysis; Graphene; Graphite - chemistry; Magnetite; Magnetite Nanoparticles - chemistry; Magnetite Nanoparticles - ultrastructure; Magnetite nanorods; Materials Testing; Nanocomposites - chemistry; Nanocomposites - ultrastructure; Nanorods; Nanostructure; Nanotubes - chemistry; Nanotubes - ultrastructure; Oxides - chemistry; Particle Size; Restacking; Sensitivity; Sensors; Synthesis
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2014.08.085

Magnetite (Fe3O4) nanorods anchored over reduced graphene oxide (rGO) were synthesized through a one-pot synthesis method, where the reduction of GO and in-situ generation of Fe3O4 nanorods occurred concurrently. The average head and tail diameter of Fe3O4 nanorods anchored over the rGO matrix are found to be 32 and 11nm, respectively, and morphology, structure and diameter of bare Fe3O4 nanorods were not altered even after the composite formation with rGO. The increased structural disorders and decrement in the sp2 domains stimulated the high electrical conductivity and extended catalytic active sites for the prepared rGO/Fe3O4 nanocomposite. The constructed rGO/Fe3O4/GCE sensor exhibited excellent electrocatalytic activity toward the electrooxidation of dopamine (DA) with a quick response time of 6s, a wide linear range between 0.01 and 100.55µM, high sensitivity of 3.15µAµM−1cm−2 and a lower detection limit of 7nM. Furthermore, the fabricated sensor exhibited a practical applicability in the quantification of DA in urine samples with an excellent recovery rate. The excellent electroanalytical performances and straight-forward, surfactant and template free preparation method construct the rGO/Fe3O4 composite as an extremely promising material for the diagnosis of DA related diseases in biomedical applications. •Reduction of GO and insitu generation of Fe3O4 nanorods occurred concurrently.•Fe(III)/Fe(II) ion centers involved DA oxidation mechanism has been detailed.•Synergetic interaction between Fe3O4 nanorods and rGO improved DA electroxidation.•rGO/Fe3O4 composite exhibited a faster amperometric response with a LOD of 7nM.•The sensor displayed good analytical reliability in human urine samples.