Photoacoustic flow measurements by use of laser-induced shape transitions of gold nanorods
Photoacoustic flow measurements by use of laser-induced shape transitions of gold nanorods
复制标题
DOI：
10.1364/ol.30.003341
复制
发表时间：
2005-12-15
期刊：
影响因子：
3.6
通讯作者：
Wang, CRC
中科院分区：
文献类型：
--
作者：
Li, PC;Huang, SW;Wang, CRC
提出了一种基于冲洗分析的流量定量测量技术。该技术利用了金纳米棒光吸收的形状依赖性和脉冲激光照射引起的形状转变。光子诱导的金纳米棒的形状转变主要包括棒到球的转换和光吸收峰波长的移动。当金纳米棒流过感兴趣的区域时，一系列激光脉冲的应用将诱导其形状发生变化，定量流动信息可从辐照金纳米棒的光声信号中获得，并作为时间函数进行测量。为了证明该技术的可行性，使用1064 nm的Nd:YAG激光进行照射，使用1 MHz的超声波换能器进行声检测。流速范围为0.35 ~ 2.83 mm/s。实测速度与实际速度吻合良好，线性回归相关系数为0.93。本研究是光声成像中冲刷流估计的先驱工作。(c) 2005年美国光学学会。
A quantitative technique for flow measurements based on a wash-in analysis is proposed. The technique makes use of the shape dependence of the optical absorption of gold nanorods and the transitions in their shape induced by pulsed laser irradiation. The photon-induced shape transition of gold nanorods involves mainly a rod-to-sphere conversion and a shift in the peak optical absorption wavelength. The application of a series of laser pulses will induce shape changes in gold nanorods as they flow through a region of interest, with quantitative flow information being derived from the photoacoustic signals from the irradiated gold nanorods measured as a function of time. To demonstrate the feasibility of the technique, a Nd:YAG laser operating at 1064 nm was used for irradiation and a 1 MHz ultrasonic transducer was used for acoustic detection. The flow velocity ranged from 0.35 to 2.83 mm/s. Excellent agreement between the measured velocities and the actual velocities was demonstrated, with a linear regression correlation coefficient of 0.93. This study is a pioneer work on wash-in flow estimation in photoacoustic imaging. (c) 2005 Optical Society of America.