Researchers develop a new method to detect subtle changes in porphyrine molecules.

A research team led by Dr. Huang Qing of the Hefei Physical Institutes of the Academy of Sciences of China has developed a new method using low frequency Raman spectroscopy to detect extremely subtle changes in the structure of porphyrine molecules , change traditional techniques often not to capture.

The work is published in Spectrochimica Acts Part A: Molecular and biomolecular spectroscopy.

Small deformations outside the plane (OOP) of metalloporphirine molecules are important for the biological functions of many enzymes. However, these deformations are too small and vary slightly between the molecules, which makes them difficult to detect using traditional methods.

In contrast, Raman Resonance spectroscopy offers a more effective means to identify structural characteristics in such molecules. However, until now, the relationship between specific deformations and changes in the maximum frequencies of Raman has remained without clear, due to the complexity of molecular interactions and the difficulty of measuring low frequency Raman signals.

In this study, the team focused on nickel porphyrin as a model molecule and used calculations of the functional density theory to explore the correlation between two biologically relevant deformations (Recupating and Silling) and Raman spectral changes.

Then, the researchers applied their method to three different types of nickel porphyrins, successfully capturing Raman spectra with frequencies as low as about 10 cm.^-1that revealed different patterns.

They discovered that the three porphyrins showed similar deformations, with only small differences in their deformations.

The most important thing, discovered that the change in a particular Raman peak (the γ₁₈ PEK) could be directly related to the degree of deformation of the carter in these molecules. This relationship means that γ₁₈ The peak can now serve as a reliable indicator to detect subtle structural changes in porphyrins.

This study not only shows how low frequency RAMAN changes can detect OOP deformations in porphyrine molecules caused by environmental changes, but also provides a useful tool for understanding how these deformations affect their biological functions.