. Author manuscript; available in PMC: 2026 May 23.

Published in final edited form as: Appl Phys Rev. 2025 Nov 6;12(4):041312. doi: 10.1063/5.0244025

TABLE I.

Amide I band is sensitive to protein secondary structure in infrared and Raman spectroscopy.

Protein secondary structures and corresponding range for component peaks (cm⁻¹)
	α-helix	β-sheet	β-turn	disordered

Infrared^a	1647–1668	1600–1645, 1682–1699	1668–1682	1645–1647
Raman^b	1649–1660	1620–1648, 1665–1680	1658–1680, 1680–1699	1660–1665

From Ref. 12 after reviewing Refs. 28–30 and 38–40.

From Ref. 41 validated by circular dichroism and x-ray, additional Refs. 31, 34, and 42–44.