FeMoO4 based, enzyme-free electrochemical biosensor for ultrasensitive detection of norepinephrine

Biosens Bioelectron. 2016 Jul 15:81:445-453. doi: 10.1016/j.bios.2016.03.029. Epub 2016 Mar 15.

Abstract

Herein, FeMoO4 (FM) nanorods were synthesized by a template-free, facile, hydrothermal method in an aqueous medium. The surface morphology of FeMoO4 was identified with field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). X-ray diffraction (XRD) was performed to identify the crystallographic nature of the as-synthesized FeMoO4. The as-synthesized material was used as an active electrode material for the oxidation of a neurotransmitter (i.e. norepinephrine (NE)) by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. FeMoO4 possesses polycrystallanity and bimetallic character, which helps to enhance the performance of the FM/GCE as compared to the GCE. The enhanced performance was also due to the formation of Fe (II)-dioxygen complexes, which catalyze the oxidation of NE. Meticulous observations taken from CV studies proved the diffusion-controlled nature of the reaction with a diffusion coefficient of 1.10×10(-4)cm(2)/s and a standard heterogeneous rate constant of 4.078×10(-3)cm/s. The amperometric response of NE on the FM/GCE showed a linear increase in the current between 5.0×10(-8)M and 2.0×10(-4)M with a detection limit of 3.7×10(-9)M. In the amperometric study, the time required to reach the 98% steady state response, after successive additions of 50nM NE, was less than 3s. The FM/GCE showed good sensitivity, and stability for the determination of NE.

Keywords: Biosensor; Electrochemical; Fe (II)-Dioxygen complex; FeMoO(4); Nanorods; Norepinephrine.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adrenergic alpha-Agonists / analysis*
  • Biosensing Techniques / methods
  • Electrochemical Techniques / methods*
  • Iron Compounds / chemistry*
  • Limit of Detection
  • Molybdenum / chemistry*
  • Nanotubes / chemistry*
  • Nanotubes / ultrastructure
  • Norepinephrine / analysis*
  • Oxidation-Reduction

Substances

  • Adrenergic alpha-Agonists
  • Iron Compounds
  • molybdate
  • Molybdenum
  • Norepinephrine