Electrosynthesis and electrochemical characteristics of 2,2′-(4,5-dihydroxy-3-methoxy-1,2-phenylene)bis(3-oxo-3-phenylpropanenitrile): application as a mediator for determination of hydroxylamine at a carbon nanotube modified electrode surface

Abstract

Electrosynthesis and electrochemical characteristics of an electrodeposited DMPP film on a multi-wall carbon nanotube modified glassy carbon electrode and its role as a mediator for electrocatalytic oxidation of hydroxylamine.

A new electro-generated o-dianisidine derivative stabilized MWCNT-modified GCE for low potential gallic acid detection

“…If the quinone product was formed on the electrode at a negative potential during continuous cycling, a well-dened redox couple responsible for quinone would be observed at À0.2 V due to the OH generation and immobilization within the electrode surface. [1][2][3][4][5][6][7][8] In addition, quinone formation from the electrochemical conversion of a methoxy group to a hydroxyl group occurs via a ketone group at acidic and alkaline pH. 3,4 This type of conversion occurred only in the presence of a hydroxyl group located in the carbon ring of the parent compound in the ortho position of the methoxy group.…”

“…[1][2][3][4][5][6][7][8] In addition, quinone formation from the electrochemical conversion of a methoxy group to a hydroxyl group occurs via a ketone group at acidic and alkaline pH. 3,4 This type of conversion occurred only in the presence of a hydroxyl group located in the carbon ring of the parent compound in the ortho position of the methoxy group. 3,4 To determine the possibility for direct conversion of the methoxy group present in o-dianisidine to a hydroxyl group in the absence of any hydroxyl functional groups in the chemical structure of the parent o-dianisidine, CV was carried out between À0.1 V and 0.7 V. At this stage, no reversible peaks were expected for the direct demethylation to the hydroxyl functional group.…”

“…3,4 This type of conversion occurred only in the presence of a hydroxyl group located in the carbon ring of the parent compound in the ortho position of the methoxy group. 3,4 To determine the possibility for direct conversion of the methoxy group present in o-dianisidine to a hydroxyl group in the absence of any hydroxyl functional groups in the chemical structure of the parent o-dianisidine, CV was carried out between À0.1 V and 0.7 V. At this stage, no reversible peaks were expected for the direct demethylation to the hydroxyl functional group. Interestingly, the appearance of anodic oxidation peak at +0.22 V gradually decreased and a strong redox couple (A2/C2) was observed at 0.2 V, which ruled out the possibility of direct demethylation to the hydroxyl group (Fig.…”

“…Carbon nanotubes (CNTs) and graphite matrices have been explored to immobilize numerous organic redox mediators and stabilize their electro-generated redox products for enhanced electro-analytical applications. [1][2][3][4][5][6][7][8] For example, the redox mediators containing amine, 1,2 methoxy, 3,4 and nitrogen 5,6 functional groups have been immobilized in these nanocarbon matrix-modied glassy carbon electrodes (GCE) at a pH of 7. In these chemically modied electrodes, the hydroxyl functional group is generated during continuous potential cycling, and therefore, the intermediate quinone species were stabilized.…”

“…[7][8][9] All of these redox products-stabilized electrodes exhibit highly sensitive, selective, stable and low potential electrochemical sensing for biological analytes. [1][2][3][4][5][6][7][8][9] However, to the best of our knowledge, the electrochemical immobilization of methoxy tethered aromatic amine based dimer structures and their electro-generated products has not been previously investigated as a mediated sensor system. Therefore, an amine-substituted aromatic benzidine redox mediator (i.e., o-dianisidine (3,3 0 -dimethoxybenzidine)) was studied to develop new electrochemical sensors for sensitive and selective low potential electroanalytical applications.…”