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

Abstract Magnetite (Fe 3 O 4 ) 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 Fe 3 O 4 nanorods occurred concurrently. The average head and tail diameter of Fe 3 O 4 nanorods anchored over the rGO matrix are found to be 32 and 11 nm, respectively, and morphology, structure and diameter of bare Fe 3 O 4 nanorods were not altered even after the composite formation with rGO. The increased structural disorders and decrement in the sp 2 domains stimulated the high electrical conductivity and extended catalytic active sites for the prepared rGO/Fe 3 O 4 nanocomposite. The constructed rGO/Fe 3 O 4 /GCE sensor exhibited excellent electrocatalytic activity toward the electrooxidation of dopamine (DA) with a quick response time of 6 s, a wide linear range between 0.01 and 100.55 µM, high sensitivity of 3.15 µA µM −1  cm −2 and a lower detection limit of 7 nM. 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/Fe 3 O 4 composite as an extremely promising material for the diagnosis of DA related diseases in biomedical applications.