Ultrafast chemical imaging by widefield photothermal sensing of infrared absorption
Ultrafast chemical imaging by widefield photothermal sensing of infrared absorption
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DOI：
10.1126/sciadv.aav7127
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发表时间：
2019-07-01
期刊：
影响因子：
13.6
通讯作者：
Cheng, Ji-Xin
中科院分区：
文献类型：
--
作者：
Bai, Yeran;Zhang, Delong;Cheng, Ji-Xin
红外（IR）成像已成为一种可行的工具，用于可视化样品中的各种化学键。然而，性能在空间分辨率和成像速度方面受到限制。在这里，而不是测量的IR光束的损失，我们使用脉冲可见光的高通量，宽视场感测的瞬态光热效应引起的吸收单个中红外脉冲。为了提取这些瞬态信号，我们构建了一个虚拟锁定相机，该相机与可见光探测器和IR光脉冲同步，具有精确控制的延迟，允许由探测脉冲宽度确定的亚微秒时间分辨率。我们的宽视场光热传感显微镜能够以高达1250帧/秒的速度进行化学成像，具有高光谱保真度，同时提供亚微米空间分辨率。凭借对活细胞和纳米级聚合物薄膜成像的能力，宽视场光热显微镜为生物和材料样品的高通量表征开辟了一条新途径。
Infrared (IR) imaging has become a viable tool for visualizing various chemical bonds in a specimen. The performance, however, is limited in terms of spatial resolution and imaging speed. Here, instead of measuring the loss of the IR beam, we use a pulsed visible light for high-throughput, widefield sensing of the transient photothermal effect induced by absorption of single mid-IR pulses. To extract these transient signals, we built a virtual lock-in camera synchronized to the visible probe and IR light pulses with precisely controlled delays, allowing submicrosecond temporal resolution determined by the probe pulse width. Our widefield photothermal sensing microscope enabled chemical imaging at a speed up to 1250 frames/s, with high spectral fidelity, while offering submicrometer spatial resolution. With the capability of imaging living cells and nanometer-scale polymer films, widefield photothermal microscopy opens a new way for high-throughput characterization of biological and material specimens.