Direct electrochemistry of hemoglobin in dimethyldioctadecyl ammonium bromide film and its electrocatalysis to nitric oxide

Direct Electrochemistry and Electrocatalysis of Hemoglobin–TiO2 Whisker Film Modified Glassy Carbon Electrode

“…The relative cathodic peak potential (E pc ) and anodic peak potential (E pa ) were located at À 332 and À 246 mV, respectively (i.e., the formal potential (E8') is À 289 mV). The separations of peak potentials, DE p , are 86 mV, which was much larger than the peak separation of reversible process (59 mV) [19], indicating that immobilized Hb displayed a quasireversible electrochemical reaction [19 -20]. Here, E8' is close to previous report such as the incorporation of Hb within didodecyldimethylammonium bromide (DDAB)-clay film [21] and the absorption of myoglobin on the surface of acid-pretreated MWNTs by electrostatic interaction [22].…”

“…Besides, the integration of the reduction peaks give nearly constant charge values (Q) with different scan rates, suggesting that the reaction is not a diffusioncontrolled process but a surface-controlled one, as expected for immobilized systems [22]. This observation indicates that almost all of the electroactive ferric form [Hb Fe (III)] in the film is reduced to ferrous form [Hb Fe(II)] on the forward scan (toward negative potentials) and that the Hb Fe(II) produced is reoxidized to Hb Fe(III) on the reverse scan [19]. DE p slightly broadens with the increasing scan rates.…”

“…Therefore, the redox reaction of Hb on Hb À TiO 2 whisker-modified GCE is a single electron transfer process. According to Faradays law (Q ¼ nFAC) [19], the average C values of electroactive Hb can be estimated to be 2.42 Â 10 À11 mol · cm…”

Direct Electrochemistry of Hemoglobin Immobilized on Hydrophilic Ionic Liquid-chitosan-ZrO2 Nanoparticles Composite Film with Carbon Ionic Liquid Electrode as the Platform

“…[2][3][4] So proteins are often incorporated into different thin film-modified electrodes, which can enhance the direct electron transfer rate between the proteins or enzymes and the underlying electrodes. A variety of materials, such as surfactants, [5][6][7][8][9][10] sol-gels, [11][12][13] polymers, 14-17 composite films, [18][19][20][21] carbon nanotubes, [22][23][24][25][26][27] and nanoparticles [28][29][30][31][32] have been employed to immobilize enzymes. Recently, nanoparticles have attracted increasing attention in electrochemical studies for the protein electrochemistry and protein immobilization because of some noticeable advantages of nanoparticles, such as large surface area, high thermal and chemical stability, tunable porosity and biocompatibility.…”

Electron transfer reactivity and the catalytic activity of hemoglobin incorporated in dimethylaminoethyl methacrylate film

“…So, the electron transfer rate in the DMAEMA film can be as high as that in the other good films. 30 The cyclic voltammograms of the Hb-DMAEMA comodified electrode have also been recorded in various buffers with different pH values. Experimental results indicate that fine voltammograms can be obtained in a wide pH range (pH 3.0-pH 10.0) in all the test buffers such as citric acid-sodium citrate, HAc-NaAc, PBS and glycineNaOH buffers.…”