[20p-P6-1~3] 3.16 Optics and Photonics English Session

▲ [20p-P6-1] Lanthanide ions for suppression of molecular photodamages under DUV biological imaging: pH dependency

〇(M2C)YauChuen YIU¹, Yasuaki KUMAMOTO², Atsushi TAGUCHI¹, Satoshi KAWATA¹ (1.Department of Applied Physics, Osaka Univ., 2.Department of Pathology and Cell Regulation, Kyoto Prefectural Univ. of Medicine)

Keywords:Deep-UV,Raman imaging,Molecular photodegradation

Deep ultraviolet (DUV) light is vital tool for Raman analysis of biomolecules such as nucleotides and aromatic amino acids due to the resonant excitation. However, the use of DUV light for Raman imaging is practically limited since the high photon energy of DUV light easily promotes photochemical damages to the target molecules. A main pathway of the damages has been identified to be electronic transitions and subsequent ionizations of molecules under DUV exposure. Depletion of the excited energy state in molecules can thus be a solution to protect the molecules from DUV photochemical damages. We have recently demonstrated the use of Terbium (Tb³⁺), europium (Eu³⁺), known as energy quenchers for nucleotide bases and aromatic amino acids [1], and thulium (Tm³⁺), as protecting agents for biological cells from the molecular photodegradation during DUV Raman imaging [2]. Here we report the influence of the solution pH on the protection effects for better understanding of the role of lanthanide ion for molecular protection under DUV exposure. Our results show that the protection effect can depend on the pH of the lanthanide ions solution. Details will be discussed in the presentation.

Reference:
[1] Frederick S. Richardson, “Terbium (III) and Europium (III) Ions as Luminescent Probes and Stains for Biomolecular Systems”, Chemical Reviews, 82, (5), 541-552, (1982)
[2] Y. Kumamoto et al., “Deep-UV biological imaging by lanthanide ion molecular protection”, Biomedical Optics Express, 7, (1), 158-170, (2016)