Redox Reaction of DNA-Encased HiPco Carbon Nanotubes with Hydrogen Peroxide: A Near Infrared Optical Sensitivity and Kinetics Study
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- 作者：Xiaomin Tu ; Pehr E. Pehrsson ; Wei Zhao
- 刊名：Journal of Physical Chemistry C
- 出版年：2007
- 出版时间：November 22, 2007
- 年：2007
- 卷：111
- 期：46
- 页码：17227 - 17231
- 全文大小：122K
- 年卷期：v.111,no.46(November 22, 2007)
- ISSN：1932-7455
文摘
The near-infrared optical properties of single-walled carbon nanotubes (SWNTs) have attracted particularattention for nanobiosensors based on their redox chemistry. In this work, we studied the redox reaction ofsingle-stranded DNA (ssDNA)-encased HiPco nanotubes with hydrogen peroxide. The absorption intensityof the near-infrared interband transitions of semiconducting nanotubes decays exponentially with reactiontime. The rate constant increases linearly with the H2O2 concentration, consistent with pseudo first-orderkinetics. The spectral changes are reversible by tuning the pH, and the sensitivity is enhanced at lowerpH 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 H2O2 is determined by three different methods basedon the concentration-dependent rate constant, spectral intensity change, and signal-to-noise ratio. Ourcurrent work provides new insights into the solution chemistry of the ssDNA-SWNT hybrids for opticalbiosensing.