Enhanced Sensitivity for Biosensors: Multiple Functions of DNA-Wrapped Single-Walled Carbon Nanotubes in Self-Doped Polyaniline Nanocomposites
- 1 August 2006
- journal article
- research article
- Published by American Chemical Society (ACS) in The Journal of Physical Chemistry B
- Vol. 110 (33), 16359-16365
- https://doi.org/10.1021/jp0614897
Abstract
A nanocomposite of poly(anilineboronic acid), a self-doped polyaniline, with ss-DNA-wrapped single-walled carbon nanotubes (ss-DNA/SWNTs) was fabricated on a gold electrode by in situ electrochemical polymerization of 3-aminophenylboronic acid monomers in the presence of ssDNA/SWNTs. We used this nanocomposite to detect nanomolar concentrations of dopamine and found that the sensitivity increased 4 orders of magnitude compared to the detection at an electrode modified with only poly(anilineboronic acid). For the first time, this work reports the multiple functions of the ss-DNA/SWNTs in the fabrication and biosensor application of a self-doped polyaniline/ss-DNA/SWNT nanocomposite. First, the ss-DNA/SWNTs acted as effective molecular templates during polymerization of self-doped polyaniline so that not only was the polymerization speed increased but also the quality of the polymer was greatly improved. Second, they functioned as novel activestabilizers after the polymerization, significantly enhancing the stability of the film. Furthermore, the ss-DNA/SWNTs also acted as conductive polyanionic doping agents in the resulting polyaniline film, which showed enhanced conductivity and redox activity. Finally, the large surface area of carbon nanotubes greatly increased the density of the functional groups available for sensitive detection of the target analyte. We envision that polyaniline with other functional groups as well as other conducting polymers may be produced for different targeted applications by this approach.Keywords
This publication has 29 references indexed in Scilit:
- Electrocatalytic Oxidation of DNA-Wrapped Carbon NanotubesJournal of the American Chemical Society, 2005
- Electroactivity of Electrochemically Synthesized Poly(Aniline Boronic Acid) as a Function of pH: Role of Self-DopingChemistry of Materials, 2004
- The Role of Template in the Enzymatic Synthesis of Conducting PolyanilineJournal of the American Chemical Society, 1999
- Molecular Sensors and Sensor Arrays Based on Polyaniline MicrotubulesAnalytical Chemistry, 1999
- Carbon nanotube electrode for oxidation of dopamineBioelectrochemistry and Bioenergetics, 1996
- Microelectrochemical multitransistor devices based on electrostatic binding of electroactive anionic metal complexes in protonated poly(4-vinylpyridine): devices that can detect and distinguish up to three species simultaneouslyAnalytical Chemistry, 1993
- Correlation between adhesion hysteresis and phase state of monolayer filmsThe Journal of Physical Chemistry, 1993
- The ion selective adsorption of polystyrenesulfonate onto a polyaniline surfaceElectrochimica Acta, 1991
- Potential dependence of the conductivity of highly oxidized polythiophenes, polypyrroles, and polyaniline: finite windows of high conductivityJournal of the American Chemical Society, 1990
- Electrochemical investigations of electronically conductive polymers. 4. Controlling the supermolecular structure allows charge transport rates to be enhancedLangmuir, 1990