| Autor: |
Tu, Xiaomin, E. Pehrsson, Pehr, Zhao, Wei |
| Zdroj: |
The Journal of Physical Chemistry - Part C; November 2007, Vol. 111 Issue: 46 p17227-17231, 5p |
| Abstrakt: |
The near-infrared optical properties of single-walled carbon nanotubes (SWNTs) have attracted particular attention for nanobiosensors based on their redox chemistry. In this work, we studied the redox reaction of single-stranded DNA (ssDNA)-encased HiPco nanotubes with hydrogen peroxide. The absorption intensity of the near-infrared interband transitions of semiconducting nanotubes decays exponentially with reaction time. The rate constant increases linearly with the H2O2concentration, consistent with pseudo first-order kinetics. The spectral changes are reversible by tuning the pH, and the sensitivity is enhanced at lower pH in the pH range of 6−8. The reaction rate depends on the buffer, which follows the order MES > Tris > phosphate > TE. The detection limit for H2O2is determined by three different methods based on the concentration-dependent rate constant, spectral intensity change, and signal-to-noise ratio. Our current work provides new insights into the solution chemistry of the ssDNA−SWNT hybrids for optical biosensing. |
| Databáze: |
Supplemental Index |
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