Direct electrochemical behavior of hemoglobin at surface of Au@Fe3O4 magnetic nanoparticles

Electrocatalytic oxidation and determination of dexamethasone at an Fe3O4/PANI–CuII microsphere modified carbon ionic liquid electrode

A novel, simple, sensitive and selective electrochemical sensor based on an Fe₃O₄/PANI–Cu^II microsphere modified carbon ionic liquid electrode is constructed and utilized for the determination of dexamethasone.

Carbon disulfide mediated self-assembly of Laccase and iron oxide nanoparticles on gold surfaces for biosensing applications

A simple one-step methodology was explored to prepare enzyme-modified nanostructured electrodes for the development of biosensing interfaces. Magnetite type nanoparticles conjugated with Laccase were immobilized on gold surfaces. This approach relies on the reaction between carbon disulfide and amine groups of biomolecules to form dithiocarbamate (DTC) moieties, as well as on the strong affinity between sulfur species and metals. Special emphasis was given to demonstrate DTC formation in aqueous solution and further attachment to iron oxide nanoparticles and to gold electrodes. UV-visible spectroscopy confirmed the functionalization of nanoparticles by DTC using a model secondary amine (N-hexylmethylamine). The direct attachment of modified iron oxide nanoparticles (with ca. 20 or 40nm mean sizes) to gold electrodes was investigated using the hormone epinephrine, with well-known electrochemical properties. A high amount of immobilized epinephrine and a facilitated redox conversion was observed for modified electrodes containing iron oxide nanoparticles. The success of this simple and robust method was confirmed by X-ray photoelectronic spectroscopy. Finally, the catalytic activity of modified gold with iron oxide nanoparticles and Laccase was evaluated toward 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid diammonium salt (ABTS). Chronoamperometric studies revealed a significant catalytic activity of immobilized Laccase in the presence of the nanoparticles, in particular for the largest ones (40nm), with a sensitivity for ABTS oxidation of 100mAM^-1cm^-2.

Fe3O4@Pt/MWCNT/carbon paste electrode for determination of a doxorubicin anticancer drug in a human urine sample

In this study, a Fe₃O₄@Pt nanoparticle and multi-walled carbon nanotube (MWCNT) modified carbon paste electrode was used as a fast and sensitive tool for the electrochemical determination of doxorubicin (DOX).

Bio and nanomaterials based on Fe3O4

During the past few years, nanoparticles have been used for various applications including, but not limited to, protein immobilization, bioseparation, environmental treatment, biomedical and bioengineering usage, and food analysis. Among all types of nanoparticles, superparamagnetic iron oxide nanoparticles, especially Fe₃O₄, have attracted a great deal of attention due to their unique magnetic properties and the ability of being easily chemical modified for improved biocompatibility, dispersibility. This review covers recent advances in the fabrication of functional materials based on Fe₃O₄ nanoparticles together with their possibilities and limitations for application in different fields.

Sonochemical fabrication of Fe3O4 nanoparticles on reduced graphene oxide for biosensors

This study synthesized Fe(3)O(4) nanoparticles of 30-40nm by a sonochemical method, and these particles were uniformly dispersed on the reduced graphene oxide sheets (Fe(3)O(4)/RGO). The superparamagnetic property of Fe(3)O(4)/RGO was evidenced from a saturated magnetization of 30emu/g tested by a sample-vibrating magnetometer. Based on the testing results, we proposed a mechanism of ultrasonic waves to explain the formation and dispersion of Fe(3)O(4) nanoparticles on RGO. A biosensor was fabricated by modifying a glassy carbon electrode with the combination of Fe(3)O(4)/RGO and hemoglobin. The biosensor showed an excellent electrocatalytic reduction toward H(2)O(2) at a wide, linear range from 4×10(-6) to 1×10(-3)M (R(2)=0.994) as examined by amperometry, and with a detection limit of 2×10(-6)M. The high performance of H(2)O(2) detection is attributed to the synergistic effect of the combination of Fe(3)O(4) nanoparticles and RGO, promoting the electron transfer between the peroxide and electrode surface.