Application of NiMoO₄ Nanorods for the Direct Electrochemistry and Electrocatalysis of Hemoglobin with Carbon Ionic Liquid Electrode

Abstract

In this paper NiMoO 4 nanorods were synthesized and used to accelerate the direct electron transfer of hemoglobin (Hb). By using an ionic liquid (IL) 1-butylpyridinium hexafluorophosphate (BPPF 6 ) modified carbon paste electrode (CILE) as the basic electrode, NiMoO 4 nanorods and Hb composite biomaterial was further cast on the surface of CILE and fixed by chitosan (CTS) to establish a modified electrode denoted as CTS/NiMoO 4 -Hb/CILE. UV-vis and FT-IR spectroscopic results showed that Hb in the film retained its native structures without any conformational changes. Electrochemical behaviors of Hb entrapped in the film were carefully investigated by cyclic voltammetry with a pair of well-defined and quasi-reversible redox voltammetric peaks appearing in phosphate buffer solution (PBS, pH 3.0), which was attributed to the direct electrochemistry of the electroactive center of Hb heme Fe(III)/Fe(II). The results were ascribed to the specific characteristic of NiMoO 4 nanorods, which accelerated the direct electron transfer rate of Hb with the underlying CILE. The electrochemical parameters of Hb in the composite film were further carefully calculated with the results of the electron transfer number (n) as 1.08, the charge transfer coefficient (a) as 0.39 and the electron-transfer rate constant (k s ) as 0.82 s À1. The Hb modified electrode showed good electrocatalytic ability toward the reduction of trichloroacetic acid (TCA) in the concentration range from 0.2 to 26.0 mmol/L with a detection limit of 0.072 mmol/L (3s), and H 2 O 2 in the concentration range from 0.1 to 426.0 mmol/L with a detection limit of 3.16 10 À8 mol/L (3s).

Facile fabrication and perfect cycle stability of 3D NiO@CoMoO4 nanocomposite on Ni foam for supercapacitors

“…The poor crystallization of the NiO@Co-MoO 4 nanocomposite is evidenced by the signicant reduced intensity of the diffraction peaks in composites pattern, which are favorable for composite to exhibit a high capacitive performance. [23][24][25] Fig. 1 The construction of 3D NiO@CoMoO 4 nanocomposite.…”

Boron Nitride Nanosheet Modified Electrode: Preparation and Application to Direct Electrochemistry of Myoglobin

“…CILE has been proved to be an effective working electrode in electroanalysis and electrochemical sensors with the advantages including high conductivity, excellent mechanic property and stability . The presence of IL in CPE can bind the graphite powder tightly with high conductivity remained . Also a layer of IL can be formed on the electrode surface with inherent catalytic ability .…”

Facile synthesis of NiMoO4·xH2O nanorods as a positive electrode material for supercapacitors

“…Metal molybdates, an important family of inorganic materials, have potential applications in various fields, 21 such as catalysis, 22 magnetism, 23 photoluminescence, 24 and energy storage. 20,25 Nickel molybdate exhibits excellent electrochemical properties for the electrocatalysis of hemoglobin 26 and oxygen evolution. 27 However, its supercapacitive performance has not been reported.…”