Biomedical Photonics Group, EPFL, Batiment CH, Lausanne, Switzerland.
J Biomed Opt. 2011 Mar;16(3):037005. doi: 10.1117/1.3558846.
A new optical-fiber-based spectrofluorometer for in vivo or in vitro detection of delayed fluorescence is presented and characterized. This compact setup is designed so that it can be readily adapted for future clinical use. Optical excitation is done with a nitrogen laser-pumped, tunable dye laser, emitting in the UV-vis part of the spectrum. Excitation and luminescence signals are carried to and from the biological tissues under investigation, located out of the setup enclosure, by a single optical fiber. These measurements, as well as measurements performed without a fiber on in vitro samples in a thermostable quartz cell, in a controlled-atmosphere enclosure, are possible due to the efficient collection of the laser-induced luminescence light which is collected and focused on the detector with a high aperture parabolic mirror. The detection is based on a gated photomultiplier which allows for time-resolved measurements of the delayed fluorescence intensity. Thus, relevant luminescence lifetimes, typically in the sub-microsecond-to-millisecond range, can be measured with near total rejection of the sample's prompt fluorescence. The instrument spectral and temporal resolution, as well as its sensitivity, is characterized and measurement examples are presented. The primary application foreseen for this setup is the monitoring and adjustment of the light dose delivered during photodynamic therapy.
一种用于体内或体外检测延迟荧光的新型光纤基荧光分光光度计已被提出并进行了特性描述。该紧凑的设计使其易于适应未来的临床应用。光学激发采用氮激光泵浦的可调谐染料激光器，在光谱的紫外-可见部分发射。激发和荧光信号通过单根光纤传输到位于仪器外壳外部的被研究的生物组织和从该生物组织传输出。这些测量，以及在一个恒温石英细胞中对体外样本进行的没有光纤的测量，在一个控制气氛的外壳中进行，这是因为激光诱导的荧光光的高效收集成为了可能，这些光被一个高孔径抛物面镜收集并聚焦在探测器上。检测基于门控光电倍增管，允许对延迟荧光强度进行时间分辨测量。因此，可以测量典型的在亚微秒到毫秒范围内的相关荧光寿命，同时几乎完全抑制了样品的瞬态荧光。仪器的光谱和时间分辨率以及其灵敏度已被进行了特征描述，并展示了一些测量实例。该设备的主要应用预期是监测和调整光动力疗法过程中的光剂量。
