Lu Huihui, Floris Francesco, Rensing Marc, Andersson-Engels Stefan
Biophotonics @ Tyndall, IPIC, Tyndall National Institute, University College Cork, T12 R5CP Cork, Ireland.
Photonics Packaging Group, IPIC, Tyndall National Institute, University College Cork, T12 R5CP Cork, Ireland.
Materials (Basel). 2020 May 2;13(9):2105. doi: 10.3390/ma13092105.
Fluorescence spectroscopy has been extensively investigated for disease diagnosis. In this framework, optical tissue phantoms are widely used for validating the biomedical device system in a laboratory environment outside of clinical procedures. Moreover, it is fundamental to consider that there are several scattering components and chromophores inside biological tissues and the interplay between scattering and absorption may result in a distortion of the emitted fluorescent signal. In this work, the photophysical behaviour of a set of liquid, tissue-like phantoms containing different compositions was analysed: phosphate buffer saline (PBS) was used as the background medium, low fat milk as a scatterer, Indian ink as an absorber and protoporphyrin IX (PpIX) dissolved in dimethyl formamide (DMF) as a fluorophore. We examined the collected data in terms of the impact of surfactant Tween-20 on the background medium, scattering effects and combination of scattering and absorption within a luminescent body on PpIX. The results indicated that the intrinsic emission peaks are red shifted by the scattering particles or surfactant, whilst the scattering agent and the absorbent can alter the emission intensity substantially. We corroborated that phantoms containing higher surfactant content (>0.5% Tween 20) are essential to prepare stable aqueous phantoms.
荧光光谱法已被广泛用于疾病诊断研究。在此框架下，光学组织模型在临床程序之外的实验室环境中被广泛用于验证生物医学设备系统。此外，必须考虑到生物组织内部存在多种散射成分和发色团，散射与吸收之间的相互作用可能会导致发射的荧光信号发生畸变。在这项工作中，分析了一组含有不同成分的液体、类组织模型的光物理行为：磷酸盐缓冲盐水（PBS）用作背景介质，低脂牛奶用作散射体，印度墨水用作吸收剂，溶解在二甲基甲酰胺（DMF）中的原卟啉IX（PpIX）用作荧光团。我们从表面活性剂吐温-20对背景介质的影响、散射效应以及发光体内散射与吸收的组合对PpIX的影响等方面检查了收集到的数据。结果表明，本征发射峰因散射颗粒或表面活性剂而发生红移，而散射剂和吸收剂可大幅改变发射强度。我们证实，含有较高表面活性剂含量（>0.5%吐温20）的模型对于制备稳定的水性模型至关重要。
