Calibration-Free Laser-Induced Breakdown Spectroscopy (CF-LIBS): Sample Preparation for Biological Tissue

Calibration-free Laser-induced Breakdown Spectroscopy (CF-LIBS) has the significant advantage of not requiring any sample preparation, making it an attractive technique for various applications.However, to prevent sample dehydration during measurements and facilitate handling, some degree of preparation is often necessary, particularly for biological samples.The flexible structures and inherent inhomogeneity of biological tissues make it difficult to achieve optimal focus and increase the risk of elemental changes during measurement, which can adversely affect reproducibility.This study investigates the analysis of porcine skin, with the ultimate aim of applying CF-LIBS in medical contexts.The effect of embedding porcine skin samples in phosphate-buffered saline (PBS) or deionised water (dHO) was therefore evaluated in comparison to untreated tissue.The results showed no significant differences between PBS and dH2O.However, distinct intensity deviations for magnesium and calcium were observed in embedded samples compared to untreated samples.Although embedding improves sample handling and reduces standard deviation, there may be an elemental exchange with the solution.Therefore, a careful compromise must be made between practical sample handling and potential elemental changes for any biological CF-LIBS application.This work provides valuable findings to advance CF-LIBS in biological and clinical research.