Optical Probing of Local pH and Temperature in Complex Fluids with Covalently Functionalized, Semiconducting Carbon Nanotubes
Optical Probing of Local pH and Temperature in Complex Fluids with Covalently Functionalized, Semiconducting Carbon Nanotubes
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DOI：
10.1021/jp509546d
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发表时间：
2015-02-19
影响因子：
3.7
通讯作者：
Wang, YuHuang
中科院分区：
文献类型：
--
作者：
Kwon, Hyejin;Kim, Mijin;Wang, YuHuang
我们表明，局部pH值可以通过缺陷光致发光从半导体碳纳米管共价官能化氨基芳基基团的光学探测。在质子化和去质子化形式的氨基部分之间的切换在近红外区域中产生多达33毫电子伏的官能化纳米管的缺陷态的能量偏移。这一意想不到的观察使一种新的光学pH传感器，具有超亮近红外II（1.1-1.4 μ m）的光致发光，pH值变化的灵敏度小至0.2 pH单位在一个广泛的工作窗口，覆盖整个生理pH范围，并可能分子分辨率。独立的pH值，这种纳米探针可以同时作为一个纳米温度计，通过监测温度调制的光致发光强度的变化，这遵循vant霍夫方程。这项工作为定量探测复杂生物系统中的局部pH值和温度变化开辟了新的机会。
We show that local pH can be optically probed through defect photoluminescence from semiconducting carbon nanotubes covalently functionalized with aminoaryl groups. Switching between protonated and deprotonated forms of the amino moiety produces an energy shift in the defect state of the functionalized nanotube by as much as 33 meV in the near-infrared region. This unexpected observation enables a new optical pH sensor that features ultrabright near-infrared II (1.1-1.4 mu m) photoluminescence, a sensitivity for pH changes as small as 0.2 pH units over a wide working window that covers the entire physiologic pH range, and potentially molecular resolution. Independent of pH, this nanoprobe can simultaneously act as a nanothermometer by monitoring temperature-modulated changes in photoluminescence intensity, which follows the vant Hoff equation. This work opens new opportunities for quantitative probing of local pH and temperature changes in complex biological systems.