Differential Laser-Induced Perturbation Spectroscopy for Analysis of Mixtures of the Fluorophores l-Phenylalanine, l-Tyrosine and l-Tryptophan Using a Fluorescence Probe

• Published in: Photochemistry and photobiology 2016-09, Vol.92 (5), p.658-666
• Main Authors: Oztekin, Erman K., Hahn, David W.
• Format: Article
• Language: English
• Subjects: Fluorescent Dyes - analysis; Fluorescent Dyes - chemistry; Lasers; Phenylalanine - analysis; Phenylalanine - chemistry; Spectrometry, Fluorescence; Spectrum analysis; Tryptophan - analysis; Tryptophan - chemistry; Tyrosine - analysis; Tyrosine - chemistry
• ISSN: 0031-8655; 1751-1097
• DOI: 10.1111/php.12618

Quantitative detection of common endogenous fluorophores is accomplished using differential laser‐induced perturbation spectroscopy (DLIPS) with a 193‐nm UV fluorescence probe and various UV perturbation wavelengths. In this study, DLIPS is explored as an alternative to traditional fluorescence spectroscopy alone, with a goal of exploring natural fluorophores pursuant to biological samples and tissue analysis. To this end, aromatic amino acids, namely, l‐phenylalanine, l‐tyrosine and l‐tryptophan are mixed with differing mass ratios and then classified with various DLIPS schemes. Classification with a traditional fluorescence probe is used as a benchmark. The results show a 20% improvement in classification performance of the DLIPS method over the traditional fluorescence method using partial least squares (PLS) analysis. Additional multivariate analyses are explored, and the relevant photochemistry is elucidated in the context of perturbation wavelengths. We conclude that DLIPS is a promising biosensing approach with potential for in vivo analysis given the current findings with fluorophores relevant to biological tissues. Differential laser‐induced perturbation spectroscopy (DLIPS) combines traditional fluorescence spectroscopy with a deep UV laser perturbation step, providing new spectroscopic information. In this study, quantitative detection of endogenous fluorophores is accomplished using DLIPS with a 193‐nm UV fluorescence probe and various UV perturbation wavelengths. To this end, aromatic amino acids, namely, l‐phenylalanine, l‐tyrosine and l‐tryptophan are mixed with differing mass ratios and then classified with various DLIPS schemes with PLS analysis. Classification with a traditional fluorescence probe is used as a benchmark. The results show a 20% improvement in classification performance of the DLIPS method over the traditional fluorescence.