Journal
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
Volume 387, Issue 3, Pages 1075-1082Publisher
SPRINGER HEIDELBERG
DOI: 10.1007/s00216-006-0992-2
Keywords
sol-gel; covalent immobilization; toluidine blue; amperometry; hydrogen peroxide
Ask authors/readers for more resources
A carbon composite amperometric hydrogen peroxide sensor has been developed using a sol-gel technique. Toluidine blue (TB), which acts as the redox mediator, was covalently immobilized via glutaraldehyde crosslinking with an organically modified silane, namely 3-aminopropyltrimethoxysilane (APTMOS). Methyltrimethoxysilane (MTMOS) was used as the additional monomer; this controls the hydrophobicity of the electrode surface, thus limiting the wettability. The immobilization of TB within the sol-gel matrix was confirmed with FTIR studies. The sol-gel mixture containing TB immobilized in APTMOS and MTMOS was mixed with graphite powder in order to prepare the carbon composite electrode. The electrode was characterized using voltammetric techniques and its electrocatalytic activity for the reduction of hydrogen peroxide was also studied. The carbon composite electrode has the advantage of sensing H2O2 at a lower potential and with a higher sensitivity, and interferences due to ascorbic acid, uric acid and acetaminophen were greatly minimized. The linear range for the determination of H2O2 extends from 5.37x10(-6) to 6.15x10(-3) M, with a correlation coefficient of 0.9981. The detection limit was found to be 2.15x10(-6) M. The covalent immobilization of TB effectively prevents the leakage of the water-soluble mediator during measurements. The modified electrode, aside from electrocatalyzing the reduction of H2O2, exhibits distinct advantages in terms of surface renewal in the event of surface fouling, as well as simple preparation, good chemical and mechanical stability, and good reproducibility.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available