Amperometric biosensors based on redox polymer-carbon nanotube-enzyme composites.
Based on their size and unique electrical properties, carbon nanotubes offer the exciting possibility of developing ultrasensitive, electrochemical biosensors. In this study, we describe the construction of amperometric biosensors based on the incorporation of single-walled carbon nanotubes modified with enzyme into redox polymer hydrogels. The composite films were constructed by first incubating an enzyme in a single-walled carbon nanotube (SWNTs) solution and then cross-linking within a poly[(vinylpyridine)Os(bipyridyl)(2)Cl(2+/3+)] polymer film. Incorporation of SWNTs, modified with glucose oxidase, into the redox polymer films resulted in a 2-10-fold increase in the oxidation and reduction peak currents during cyclic voltammetry, while the glucose electrooxidation current was increased 3-fold to approximately 1 mA/cm(2) for glucose sensors. Similar effects were also observed when SWNTs were modified with horseradish peroxidase prior to incorporation into redox hydrogels.
Joshi
Pratixa P
PP
University of Oklahoma Bioengineering Center, School of Chemical, Biological and Materials Engineering, University of Oklahoma, 100 East Boyd, Norman, Oklahoma 73019, USA.
Merchant
Stephen A
SA
Wang
Youdan
Y
Schmidtke
David W
DW
D015374:Biosensing Techniques / Q000379:methods*; D003432:Cross-Linking Reagents / Q000737:chemistry; D004563:Electrochemistry; D004800:Enzymes, Immobilized; D005947:Glucose / Q000737:chemistry; D005949:Glucose Oxidase / Q000737:chemistry / Q000378:metabolism; D006735:Horseradish Peroxidase / Q000737:chemistry / Q000378:metabolism; D020100:Hydrogels / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry; D037742:Nanotubes, Carbon / Q000737:chemistry*; D010084:Oxidation-Reduction; D011108:Polymers / Q000737:chemistry*; D011145:Polyvinyls / Q000737:chemistry; D011725:Pyridines / Q000737:chemistry
D003432:Cross-Linking Reagents; D004800:Enzymes, Immobilized; D020100:Hydrogels; D037742:Nanotubes, Carbon; D011108:Polymers; D011145:Polyvinyls; D011725:Pyridines; D006861:Hydrogen Peroxide; D005949:Glucose Oxidase; D006735:Horseradish Peroxidase; D005947:Glucose