Influence of Sample Preparation Methods for Porcine Tissue: Calibration-Free LIBS for In Vivo Applications

Area of Science:

• Analytical Chemistry
• Biomedical Spectroscopy

Background:

• Calibration-free laser-induced breakdown spectroscopy (CF-LIBS) offers simplified sample analysis.
• Biological tissue sample preparation can influence spectral data in LIBS analysis.

Purpose of the Study:

• To evaluate the impact of different preparation methods on porcine tissue analysis using CF-LIBS.
• To determine the reliability of CF-LIBS for analyzing untreated biological samples.

Main Methods:

• Porcine tissue samples were prepared by embedding in PBS or deionized water, cryo-sectioning, or left untreated.
• Samples were analyzed using calibration-free laser-induced breakdown spectroscopy (CF-LIBS).
• Elemental intensity ratios (e.g., Mg/Na) were compared across preparation methods.

Main Results:

• Embedding porcine tissue in aqueous solutions (PBS, deionized water) altered LIBS spectra, particularly minor deviations in Mg/Na ratios in skin.
• Ionic exchange between embedded samples and immersion media can affect elemental signatures.
• Untreated samples showed spectral shifts due to post-mortem changes, highlighting the need for immediate analysis.

Conclusions:

• CF-LIBS can be reliably applied to untreated biological samples, minimizing sample preparation.
• Immediate analysis of fresh biological tissues is essential for accurate elemental quantification.
• CF-LIBS shows promise for in vivo diagnostics due to its minimal sample preparation requirements.