Direct electrochemistry and electrocatalysis of heme-proteins entrapped in agarose hydrogel films

An Amperometric Nitrite Biosensor Based on the Bioelectrocatalysis of Hemoglobin Incorporated in Sol-gel Film

“…It can be seen that the Hb-PNM film absorption spectrum exhibits a strong heme Soret band at nearly 412 nm in the range of pH 5.0 ~ 9.0, However, when pH was decreased to below 4.0, the 412 nm Soret band absorption shifted and became broader and smaller (Fig 1d), indicative of a great change in heme pocket. These results are in agreement with those of Palaniappan [13] and Liu [14]. These results coincide well with previous studies on Hb immobilized in other films [16,17].…”

A Novel NH2/ITO Ion Implantation Electrode: Preparation, Characterization, and Application in Bioelectrochemistry

“…The formal potentials E8' which is estimated as the midpoint of reduction and oxidation peak potentials, has linear relationship with pH (from 6.06 to 8.3). The slopes of E8' versus pH was 42.6 mV/ pH, which was smaller than the theoretical value of 57.6 mV/pH at 18 8C for one electron and one proton reaction, which might be resulted from the influence of protonation states of amino acids near the heme and protonation of the water molecule coordinated to the heme iron [40,41]. The stability of the Mb/MWNTs/NH 2 /ITO electrode was also studied by cyclic measurements of 0.5 mM H 2 O 2 in 0.5 M PBS.…”

Direct Electrochemistry and Electrocatalysis of Myoglobin Immobilized on Gold Nanoparticles/Carbon Nanotubes Nanohybrid Film

“…The formal potentials E 0 ' which is estimated as the midpoint of reduction and oxidation peak potentials, has linear relationship with pH (from 4.16 to 8.56). The slopes of E 0 versus pH was 42.2 mV/ pH, which was smaller than the theoretical value of 57.6 mV/pH at 18 8C for one electron and one proton reaction [31], which might be resulted from the influence of protonation states of amino acids near the heme and protonation of the water molecule coordinated to the heme iron [32,33].…”