Department of Biochemistry and Cell Biology, Rice University, Houston, Texas 77005, United States.
Langmuir. 2012 Mar 13;28(10):4858-66. doi: 10.1021/la205132x. Epub 2012 Feb 28.
The photothermal efficacy of near-infrared gold nanoparticles (NP), nanoshells, and nanorods was studied under pulsed high-energy optical excitation in plasmonic nanobubble (PNB) mode as a function of the wavelength and duration of the excitation laser pulse. PNBs, transient vapor nanobubbles, were generated around individual and clustered overheated NPs in water and living cells. Transient PNBs showed two photothermal features not previously observed for NPs: the narrowing of the spectral peaks to 1 nm and the strong dependence of the photothermal efficacy upon the duration of the laser pulse. Narrow red-shifted (relative to those of NPs) near-infrared spectral peaks were observed for 70 ps excitation laser pulses, while longer sub- and nanosecond pulses completely suppressed near-infrared peaks and blue shifted the PNB generation to the visual range. Thus, PNBs can provide superior spectral selectivity over gold NPs under specific optical excitation conditions.
研究了近红外金纳米粒子（NP）、纳米壳和纳米棒在等离子体纳米泡（PNB）模式下的光热效能，作为激发激光脉冲波长和持续时间的函数。PNB 是在水和活细胞中单个过热 NP 和聚集 NP 周围产生的瞬态蒸汽纳米泡。瞬态 PNB 表现出两个以前在 NP 中未观察到的光热特征：光谱峰的变窄至 1nm 以及光热效率对激光脉冲持续时间的强烈依赖性。对于 70ps 激发激光脉冲，观察到近红外光谱峰的窄红移（相对于 NP），而较短的亚纳秒和纳秒脉冲则完全抑制了近红外峰，并将 PNB 的产生蓝移到可见范围。因此，在特定的光学激发条件下，PNB 可以提供优于金 NP 的光谱选择性。
