Time-gated Raman spectroscopy for biomedical application under ambient or strong background light conditions
Time-gated Raman spectroscopy for biomedical application under ambient or strong background light conditions
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DOI：
10.1088/1361-6463/ac276e
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发表时间：
2021-12-16
影响因子：
3.4
通讯作者：
Notingher, Ioan
中科院分区：
文献类型：
--
作者：
Corden, Christopher;Boitor, Radu;Notingher, Ioan
许多生物医学应用需要在环境照明条件下测量组织的拉曼光谱。然而，背景光常常淹没较弱的拉曼信号。研究了基于时间相关单光子计数和近红外激光激发的单光子雪崩二极管（SPAD）的时间选通（TG）拉曼光谱技术在生物组织拉曼光谱和光谱图像采集中的应用。使用动物组织样品（脂肪组织和肌肉）获得的结果表明，时间选通模态使得能够在与不存在背景光的常规连续波拉曼光谱类似的质量的背景光条件下测量拉曼光谱。对于300-1000 ps的时间门宽度，观察到背景光的最佳抑制。结果还表明，TG拉曼光谱能够检测医疗诊断所需的细微光谱差异，例如癌症和正常组织的拉曼光谱差异。虽然目前的仪器需要扫描光栅，以获得完整的拉曼光谱，导致多波数拉曼映射不切实际的时间，成像时间可以大大减少光谱复用（压缩检测）使用数字拉曼装置或通过使用SPAD阵列。
Many biomedical applications require measurements of Raman spectra of tissue under ambient lighting conditions. However, the background light often swamps the weaker Raman signal. The use of time-gated (TG) Raman spectroscopy based on a single photon avalanche diode (SPAD) operating in time-correlated single photon counting and near-infrared laser excitation was investigated for acquisition of Raman spectra and spectral images of biological tissue. The results obtained using animal tissue samples (adipose tissue and muscle) show that the time gating modality enables measurement of Raman spectra under background light conditions of similar quality as conventional continuous wave Raman spectroscopy in the absence of background light. Optimal suppression of the background light was observed for time gate widths of 300-1000 ps. The results also showed that TG Raman spectroscopy was able to detect subtle spectral differences required for medical diagnostics, such as differences in Raman spectra of cancer and normal tissue. While the current instrument required scanning of the grating in order to obtain full Raman spectra, leading to impractical times for multi-wavenumber Raman mapping, imaging time could be drastically reduced by spectral multiplexing (compressed detection) using digital micromirror devices or by using SPAD arrays.