This review discusses the application of linearly polarized infrared spectroscopy (p-IR) in the analysis of biological materials, with a focus on biomolecules, cells, and tissues. It explains how p-IR can provide insights into the structure and orientation of these materials. While initially used to study model biomolecules, recent developments in p-IR techniques, such as polarization-resolved mapping and imaging, have enabled researchers to analyze biomolecules within excised tissues. The review also mentions the advantages of p-IR over alternative techniques, including its accessibility, specificity, and minimal sample damage. It highlights the continued importance of p-IR in the analysis of biological materials, despite the availability of other methodologies.

In conclusion, this review aims to provide a comprehensive overview of p-IR, covering its theory, methodologies, instrumental configurations, and applications in the context of biological samples. It discusses the potential future directions of this field, considering emerging instrumentation and the shift towards clinical applications.