Photoacoustic probing of fluorophore excited state lifetime with application to oxygen sensing
Photoacoustic probing of fluorophore excited state lifetime with application to oxygen sensing
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DOI：
10.1117/1.2927466
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发表时间：
2008-05-01
影响因子：
3.5
通讯作者：
Kopelman, Raoul
中科院分区：
文献类型：
--
作者：
Ashkenazi, Shai;Huang, Shen-Wen;Kopelman, Raoul
提出了一种不需要收集荧光发射信号就能在混浊介质中进行荧光团激发态寿命局域测量的新方法。该方法是基于泵浦-探测方法，其中第一激光脉冲激发染料，然后第二激光脉冲用于瞬态吸收的光声探测。由探测脉冲产生的光声响应由超声接收器记录。重复测量以增加泵浦-探测时间延迟，产生一系列用于提取激发态寿命的光声信号。通过测量不同溶解氧浓度下氧敏染料溶液的寿命来验证该方法。用532 nm脉冲激光泵浦染料，并使用第二脉冲激光系统探测740 nm处的瞬态吸收。基于光声的结果与从时间依赖性荧光测量获得的结果非常一致。该方法可以扩展到光声寿命成像，通过使用一个接收器阵列，而不是一个单一的接收器。该方法的潜在应用包括用于癌症诊断的组织氧成像和映射分子事件，例如生物环境中的共振能量转移和离子碰撞。(c)2008年，由光学仪器工程师协会（Society of Photo-Optical Instrumentation Engineers）主办。
A new method is developed to perform local measurements of fluorophore excited state lifetimes in turbid media without collecting the fluorescence emission. The method is based on a pump-probe approach where a first laser pulse excites the dye and then a second laser pulse is used for photoacoustic probing of the transient absorption. The photoacoustic response generated by the probe pulse is recorded by an ultrasound receiver. Repeating the measurement for increasing pump-probe time delays yields a series of photoacoustic signals that are used to extract the lifetime of the excited state. The method is validated by measuring the lifetime of an oxygen sensitive dye solution at different concentrations of dissolved oxygen. The dye is pumped with a 532-nm pulsed laser and the transient absorption at 740 nm is probed using a second pulsed laser system. The photoacoustic-based results are in close agreement with those obtained from time-dependent fluorescent measurements. The method can be extended to photoacoustic lifetime imaging by using a receiver array instead of a single receiver. Potential applications of this method include tissue oxygen imaging for cancer diagnostics and mapping molecular events such as resonant energy transfer and ion collisions in a biological environment. (c) 2008 Society of Photo-Optical Instrumentation Engineers.