Direct electrochemistry of hemoglobin immobilized in polyvinylalcohol and clay composite film modified carbon ionic liquid electrode

Abstract

Neste trabalho, líquido iônico hexaflúor-fosfato de 1-butil-3-metilimidazólio (BMIMPF 6 ), em temperatura ambiente, foi usado como ligante na fabricação de um eletrodo líquido iônico de carbono (CILE). Hemoglobina (Hb) foi imobilizada na superfície de CILE com argila e um filme composto por polivinil álcool (PVA) pelo método camada por camada. Espectros de UV-Vis e FT-IR mostraram que Hb no filme reteve as características essenciais de sua estrutura original. In this paper room temperature ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF 6 ) was used as binder to fabricate a carbon ionic liquid electrode (CILE). Hemoglobin (Hb) was immobilized on the surface of CILE with clay and polyvinyl alcohol (PVA) composite film by layer to layer method. UV-Vis and FT-IR spectra showed that Hb in the film retained the essential features of its native structure. Electrochemical experiments indicated that a pair of well-defined quasi-reversible redox peak was obtained in pH 7.0 Britton-Robinson (B-R) buffer solution. The reduction and oxidation peak potentials were located at −0.405 V and −0.274 V (vs. SCE) with the formal potential as −0.340 V, which was contributed to the electrochemical reaction of heme Fe(III)/Fe(II) redox couples. The results suggested that the direct electron transfer of Hb in the PVA/Clay film with the CILE was accomplished. The direct electrochemical behaviors of Hb were carefully studied with the electrochemical parameters calculated. The PVA/ Clay/Hb modified CILE gave excellent electrocatalytic ability to the reduction of H 2 O 2 and the apparent Michaelis-Menten constant (K M app ) value of Hb in the PVA/Clay film was calculated as 56.26 μmol L -1 .

A review on electrodes modified with ionic liquids

“…ILCPE were also used as easy to prepare support electrodes for wide range of deposits [148,159,165,178,179,185,190,193,197,201,202,204,215,228,[243][244][245][246][247][248][249][250][251][252][253][254][255][256][257][258]. This geometry allows for use of minute amount of material for surface modification without losing easy renewability of the surface.…”

“…Enzyme deposit covered by MWCNTs [202] represents another example. The stable layer-bylayer structure made of polyvinyl alcohol, clay and enzyme was build on the top of ILCPE [254]. Most of these electrodes exhibit direct protein voltammetry and bioelectrocatalytic properties employed for sensing.…”

Incorporação de líquidos iônicos e nanopartículas metálicas na construção de sensores eletroquímicos

“…Medidas eletroquímicas e espectroscópicas indicaram que a hemoglobina mantém sua estrutura nativa no filme de argila e PVA, e a presença do LI eleva a velocidade de transferência de elétrons. 86 Outros trabalhos empregando a hemoglobina e o LI BMI. PF 6 para o desenvolvimento de biossensores para determinação de H 2 O 2 também obtiveram resultados positivos, como boa seletividade, sensibilidade e estabilidade.…”

Direct Electron Transfer of Hemoglobin in a Hydrophilic Ionic Liquid/Gellan Gum Composite Film Modified Carbon Ionic Liquid Electrode

“…9 However, Hb does not easily undergo facile redox reactions at electrodes surfaces because of its electroactive centers embedded deeply in the protein structure. [10][11][12][13] In order to solve this problem, great efforts have been made to enhance the electron transfer of Hb using different modified films, such as surfactants, [14][15][16][17][18][19] hydrogel, 20,21 polymer, [22][23][24] composite film, [25][26][27][28] or nanoparticle. [29][30][31][32] In recent years, because of the unique physical and chemical properties, such as high chemical and thermal stability, relatively high ionic conductivity, negligible vapor pressure and wide electrochemical windows, room temperature ionic liquids (RTILs) have been used for many applications.…”