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Bimetallic Co 2+ and Mn 2+ Hexacyanoferrate for Hydrogen Peroxide Electrooxidation and Its Application in a Highly Sensitive Cholesterol Biosensor
Author(s) -
Antuch Manuel,
MatosPeralta Yasser,
Llanes Dayma,
Echevarría Frank,
RodríguezHernández Joelis,
Marin Milenen Hernández,
DíazGarcía Alicia M.,
Reguera Leslie
Publication year - 2019
Publication title -
chemelectrochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.182
H-Index - 59
ISSN - 2196-0216
DOI - 10.1002/celc.201900190
Subject(s) - prussian blue , bimetallic strip , biosensor , hydrogen peroxide , electrochemistry , redox , catalysis , chemistry , cholesterol oxidase , inorganic chemistry , electrocatalyst , detection limit , nuclear chemistry , kinetics , electrode , organic chemistry , chromatography , enzyme , biochemistry , physics , quantum mechanics
In this work, we report the synthesis and characterization of a bimetallic Prussian blue analogue containing Co and Mn as outer‐sphere metals (CoMnHCF). The material was a solid solution and its characterization revealed a chemical composition of Co 2.05 Mn 0.95 [Fe(CN) 6 ] 2 ⋅ 12H 2 O. The electrochemistry of this novel material showed the existence of two redox waves displaying quasi‐reversible kinetics, as expressed by the larger peak‐to‐peak separation upon increasing the potential sweep rate. Interestingly, the CoMnHCF solid exhibited high electrocatalytic activity for the oxidation of hydrogen peroxide, thus representing an appealing scaffold for the construction of biosensors. As a proof of concept, cholesterol oxidase was immobilized at the electrode surface by using a sol‐gel method, and the cyclic voltammograms were recorded at increasing concentrations of cholesterol. The biosensor showed a detection limit of 30 μM and two linear ranges with excellent sensitivity of 385 mA cm −2 M −1 between 50 and 150 μM, and an adequate sensitivity of 80 mA cm −2 M −1 between 150 and 1 mM. To the best of our knowledge, this is the first biosensor application of a pre‐synthesized bimetallic hexacyanometallate, thus exploiting its potential as an H 2 O 2 electrooxidation catalyst.