Improved protocols for vibrational spectroscopic analysis of body fluids

Area of Science:

• Biophysical Chemistry
• Analytical Chemistry
• Spectroscopy

Background:

• Vibrational spectroscopy, including FTIR and Raman, is explored for analyzing human blood serum.
• FTIR spectra are limited by water absorption in the high-wavenumber region.
• Raman spectroscopy shows potential for higher sensitivity and broader spectral coverage.

Purpose of the Study:

• To evaluate and improve spectroscopic methods for human blood serum analysis.
• To overcome limitations of existing techniques, such as water absorption and spectral inhomogeneity.
• To enhance spectral intensity, quality, and reproducibility for clinical applications.

Main Methods:

• Fourier Transform Infrared (FTIR) and Raman spectroscopy were employed.
• Analysis of aqueous solutions and dried deposits of human serum.
• Serum concentration using centrifugal filter devices.
• Measurement in inverted geometry for Raman spectroscopy.

Main Results:

• Raman spectroscopy achieved high-quality spectra of gelatine solutions at lower concentrations (10 mg/L) than FTIR (100 mg/L).
• Human serum spectra were weak and obscured by water features; dried deposits showed inhomogeneity.
• Serum concentration and inverted geometry Raman measurements significantly improved spectral intensity, quality, and reduced background.
• Improved protocols enhance spectral data for bodily fluids.

Conclusions:

• Raman spectroscopy is more suitable than FTIR for analyzing human serum due to its ability to overcome water absorption.
• Serum concentration and inverted geometry are effective strategies for enhancing spectral quality.
• Optimized spectroscopic protocols hold promise for accelerating clinical applications of bodily fluid analysis.