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Asmussen JD, Abid AR, Sundaralingam A, Bastian B, Sishodia K, De S, Ben Ltaief L, Krishnan S, Pedersen HB, Mudrich M. Secondary ionization of pyrimidine nucleobases and their microhydrated derivatives in helium nanodroplets. Phys Chem Chem Phys 2023; 25:24819-24828. [PMID: 37671772 DOI: 10.1039/d3cp02879h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/07/2023]
Abstract
Radiation damage in biological systems by ionizing radiation is predominantly caused by secondary processes such as charge and energy transfer leading to the breaking of bonds in DNA. Here, we study the fragmentation of cytosine (Cyt) and thymine (Thy) molecules, clusters and microhydrated derivatives induced by direct and indirect ionization initiated by extreme-ultraviolet (XUV) irradiation. Photofragmentation mass spectra and photoelectron spectra of free Cyt and Thy molecules are compared with mass and electron spectra of Cyt/Thy clusters and microhydrated Cyt/Thy molecules formed by aggregation in superfluid helium (He) nanodroplets. Penning ionization after resonant excitation of the He droplets is generally found to cause less fragmentation compared to direct photoionization and charge-transfer ionization after photoionization of the He droplets. When Cyt/Thy molecules and oligomers are complexed with water molecules, their fragmentation is efficiently suppressed. However, a similar suppression of fragmentation is observed when homogeneous Cyt/Thy clusters are formed in He nanodroplets, indicating a general trend. Penning ionization electron spectra (PIES) of Cyt/Thy are broad and nearly featureless but PIES of their microhydrated derivatives point at a sequential ionization process ending in unfragmented microsolvated Cyt/Thy cations.
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Affiliation(s)
- Jakob D Asmussen
- Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C, Denmark.
| | - Abdul R Abid
- Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C, Denmark.
| | | | - Björn Bastian
- Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C, Denmark.
| | - Keshav Sishodia
- Quantum Center of Excellence for Diamond and Emergent Materials and Department of Physics, Indian Institute of Technology Madras, Chennai 600036, India
| | - Subhendu De
- Quantum Center of Excellence for Diamond and Emergent Materials and Department of Physics, Indian Institute of Technology Madras, Chennai 600036, India
| | - Ltaief Ben Ltaief
- Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C, Denmark.
| | - Sivarama Krishnan
- Quantum Center of Excellence for Diamond and Emergent Materials and Department of Physics, Indian Institute of Technology Madras, Chennai 600036, India
| | - Henrik B Pedersen
- Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C, Denmark.
| | - Marcel Mudrich
- Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C, Denmark.
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Wang Q, Lin S, Liu X, Xu W, Xiao Y, Liang C, Ding L, Peeters FM. Photoluminescence and electronic transition behaviors of single-stranded DNA. Phys Rev E 2021; 104:034412. [PMID: 34654201 DOI: 10.1103/physreve.104.034412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Accepted: 08/31/2021] [Indexed: 11/07/2022]
Abstract
Due to the potential application of DNA for biophysics and optoelectronics, the electronic energy states and transitions of this genetic material have attracted a great deal of attention recently. However, the fluorescence and corresponding physical process of DNA under optical excitation with photon energies below ultraviolet are still not fully clear. In this work, we experimentally investigate the photoluminescence (PL) properties of single-stranded DNA (ssDNA) samples under near-ultraviolet (NUV) and visible excitations (270∼440 nm). Based on the dependence of the PL peak wavelength (λ_{em}) upon the excitation wavelength (λ_{ex}), the PL behaviors of ssDNA can be approximately classified into two categories. In the relatively short excitation wavelength regime, λ_{em} is nearly constant due to exciton-like transitions associated with delocalized excitonic states and excimer states. In the relatively long excitation wavelength range, a linear relation of λ_{em}=Aλ_{ex}+B with A>0 or A<0 can be observed, which comes from electronic transitions related to coupled vibrational-electronic levels. Moreover, the transition channels in different excitation wavelength regimes and the effects of strand length and base type can be analyzed on the basis of these results. These important findings not only can give a general description of the electronic energy states and transitional behaviors of ssDNA samples under NUV and visible excitations, but also can be the basis for the application of DNA in nanoelectronics and optoelectronics.
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Affiliation(s)
- Qiujin Wang
- School of Physics and Astronomy and Key Lab of Quantum Information of Yunnan Province, Yunnan University, Kunming 650091, China
| | - Shuo Lin
- School of Physics and Astronomy and Key Lab of Quantum Information of Yunnan Province, Yunnan University, Kunming 650091, China
| | - Xuan Liu
- School of Physics and Astronomy and Key Lab of Quantum Information of Yunnan Province, Yunnan University, Kunming 650091, China
| | - Wen Xu
- School of Physics and Astronomy and Key Lab of Quantum Information of Yunnan Province, Yunnan University, Kunming 650091, China.,Micro Optical Instruments Inc., 518118 Shenzhen, China.,Key Laboratory of Material Physics, Institute of Solid State Physics, Chinese Academy of Science, Hefei 230031, China
| | - Yiming Xiao
- School of Physics and Astronomy and Key Lab of Quantum Information of Yunnan Province, Yunnan University, Kunming 650091, China
| | - Changneng Liang
- School of Physics and Astronomy and Key Lab of Quantum Information of Yunnan Province, Yunnan University, Kunming 650091, China
| | - Lan Ding
- School of Physics and Astronomy and Key Lab of Quantum Information of Yunnan Province, Yunnan University, Kunming 650091, China
| | - F M Peeters
- School of Physics and Astronomy and Key Lab of Quantum Information of Yunnan Province, Yunnan University, Kunming 650091, China.,Department of Physics, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerpen, Belgium
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