Vibrational circular dichroism (VCD) spectroscopy has emerged as a powerful platform to quantify chirality, a vital biological property that performs a pivotal role in the metabolism of life organisms. With a photoelastic modulator (PEM) integrated into an infrared spectrometer, the differential response of a sample to the direction of circularly polarized light can be used to infer conformation handedness. However, these optical components inherently exhibit chromatic behavior and are typically optimized at discrete spectral frequencies. Advancements of discrete frequency infrared (DFIR) spectroscopic microscopes in spectral image quality and data throughput are promising for use toward analytical VCD measurements. Utilizing the PEM advantages incorporated into a custom-built QCL microscope, we demonstrate a point scanning VCD instrument capable of acquiring spectra rapidly across all fingerprint region wavelengths in transmission configuration. Moreover, for the first time, we also demonstrate the VCD imaging performance of our instrument for site-specific chirality mapping of biological tissue samples. This study offers some insight into future possibilities of examining small, localized changes in tissue that have major implications for systemic diseases and their progression, while also laying the groundwork for additional modeling and validation in advancing the capability of VCD spectroscopy and imaging.

中文翻译：

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红外光谱成像同步振动圆二色性测量

振动圆二色性 (VCD) 光谱已成为量化手性的强大平台，手性是一种重要的生物学特性，在生命有机体的新陈代谢中发挥着关键作用。通过将光弹性调制器 (PEM) 集成到红外光谱仪中，样品对圆偏振光方向的微分响应可用于推断构象旋向性。然而，这些光学元件固有地表现出彩色行为，并且通常在离散光谱频率下进行优化。离散频率红外 (DFIR) 光谱显微镜在光谱图像质量和数据吞吐量方面的进步有望用于分析 VCD 测量。利用纳入定制 QCL 显微镜的 PEM 优势，我们展示了一种点扫描 VCD 仪器，能够在传输配置中快速获取所有指纹区域波长的光谱。此外，我们还首次展示了我们仪器的 VCD 成像性能，用于生物组织样本的位点特异性手性映射。这项研究提供了一些关于未来检查组织中微小的局部变化的可能性的见解，这些变化对全身性疾病及其进展有重大影响，同时也为进一步建模和验证以提高 VCD 光谱和成像的能力奠定了基础。我们还展示了我们仪器的 VCD 成像性能，用于生物组织样本的位点特异性手性映射。这项研究提供了一些关于未来检查组织中微小的局部变化的可能性的见解，这些变化对全身性疾病及其进展有重大影响，同时也为进一步建模和验证以提高 VCD 光谱和成像的能力奠定了基础。我们还展示了我们仪器的 VCD 成像性能，用于生物组织样本的位点特异性手性映射。这项研究提供了一些关于未来检查组织中微小的局部变化的可能性的见解，这些变化对全身性疾病及其进展有重大影响，同时也为进一步建模和验证以提高 VCD 光谱和成像的能力奠定了基础。