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Intrinsic DNA fluorescence

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The term intrinsic DNA fluorescence refers to the fluorescence emitted directly by DNA when it absorbs ultraviolet (UV) radiation. It contrasts to that stemming from labels that are attached to DNA strands, widely used in biological applications. The intrinsic DNA fluorescence was discovered in the 1960s by studying nucleic acids in frozen media.[1] Since the beginning of the 21st century, the much weaker emission of nucleic acids in fluid solutions is being studied in room temperature by means sophisticated spectroscopic techniques using as UV source femtosecond laser pulses and following the evolution of the emitted light from femtoseconds to nanoseconds.[2][3][4][5][6][7] Such studies bring information about the relaxation of the electronic excited states[8] and, thus, contribute to understanding the very first steps of a complex series of events triggered by UV radiation, ultimately leading to DNA damage.[9] Moreover, the knowledge of the fundamental processes underlying the DNA fluorescence paves the way for the development of label-free biosensors.[10][11]

Conditions for measuring the intrinsic DNA fluorescence

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Due to the weak intensity of the intrinsic DNA fluorescence, specific cautions are necessary in order to perform correct measurements and obtain reliable results.[12] A first requirement concerns the purity of both the DNA samples and that of the chemicals and the water used to the preparation of the buffered solutions. The buffer emission must be systematically recorded and, in certain cases, substracted in an appropriate way.[13] A second requirement is associated with the DNA damage provoked by the exciting UV light which alters its fluorescence.[14] Therefore, their generation during the experiment may alter the emission spectra. In order to overcome these difficulties, continuous stirring of the solution is needed. For measurements using laser excitation, the circulation of the DNA solution by means of a peristaltic pump is recommended.

Spectral shapes and quantum yields

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Steady-state fluorescence spectra of the DNA nucleosides normalized to their maximum intensity.

The fluorescence of all DNA systems in neutral aqueous solution peaks in the near ultraviolet (300-400 nm) when excited around 260 nm. In addition, a long tail, extending all over the visible domain is present in the fluorescence spectrum. The associated quantum yields Φ, that is the number of emitted photons over the number of absorbed photons, are typically in the range of 10-4-10-3. The highest values are encountered for G-quadruplexes.[15]

A limited number of measurements were also performed upon UVA excitation (330 nm), where DNA single and double strands, but not their monomeric units, absorb weakly.[16] The UVA-induced fluorescence peaks at longer wavelengths (415-430 nm) and the corresponding Φ values are at least one order of magnitude higher compared to those determined with excitation around 260 nm.[17]

Time-resolved studies, combined to theoretical calculations,[18][19] showed that the fluorescence spectrum of DNA multimers (containing more than one nucleobase) is the envelope of multiple components, arising from the electronic coupling between the close-lying nucleobases.[20] Their relative importance depends on a series of factors, such as the base sequence, the secondary structure, the viscosity of the solution or, in the case of G-Quadruplexes, the metal ions in their central cavity.[21][22][23] Due to this properties, it is possible to follow the formation[24] and the melting[25] of G-Quadruplexes by monitoring their fluorescnece emission; and the formation of hairpin loops in these structures.[26] The DNA nucleoside thymidine (dT) was proposed as a reference for the determination of small fluorescence quantum yields[27]

Time-resolved techniques

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The specificity of the intrinsic DNA fluorescence is that its decay starts already on the femtosecond time-scale and, in the cases of multimers, it is pursued on longer times, reaching, in some cases, tens of nanoseconds. Consequently, in order to obtain a complete picture of its time evolution, femtosecond laser pulses are used as excitation source. Time-resolved techniques employed to this end are fluorescence upconversion,[28][29][30] Kerr-gated fluorescence spectroscopy[31] and time-correlated single photon counting.[32] In addition to the changes in the fluorescence intensity, all of them allow the recording of time-resolved fluorescent spectra and fluorescence anisotropies,[33][34] which provide information about the relaxation of the excited electronic states and the type of the emitting excited states.

Emitting excited states and their lifetimes

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Monomeric chromophores

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Emission from the monomeric DNA chromophores, nucleosides and nucleotides, arises from their lower in energy excited state (ππ*). These are bright states, in the sense that they are also responsible for photon absorption.[35]

Cartoon representing photon absorption by the chromophore TREL and subsequent ultrafast relaxation through a conical intersection.

Their lifetimes are extremely short: they fully decay within, at most, a few ps.[36][37][38] Such ultrafast decays are due to the existence of conical intersections connecting the excited state with the ground state. As a result, the dominant deactivation pathway is non-radiative, leading to very low fluorescence quantum yields. The evolution toward the conical intersection is accompanied by conformational movements. An important part of the photons is emitted while the system is moving along the potential energy surface of the excited state, before reaching a point of minimum energy. For this reason, the fluorescence dynamics are strongly non-exponential and are not characterized by well-defined time constants, as is the case of strongly fluorescent molecules.[39]

Cartoon representing excited state relaxation via confomrational motions

An important part of the photons is emitted while the system is moving along the potential energy surface of the excited state, before reaching a point of minimum energy. For this reason, the fluorescence dynamics are strongly non-exponential and are not characterized by well-defined time constants, as is the case of the strongly fluorescent molecules.

Multichromophoric systems

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Due to their close proximity, nucleobases in DNA multimers may be electronically coupled. As a result, the excited states responsible for photon absorption (Franck-Condon states) may be delocalized over more than one nucleobase (collective or exciton states).[40][41][42][43] But the electronic coupling depends on the geometrical arrangement of the chromophores and, therefore, it is affected by the conformational disorder characterizing the nucleic acids,[44] giving rise to a large number of Franck-Condon states. Each one of them evolves along a specific energy surface.

One can distinguish two limiting types of emitting states in DNA. On the one hand, ππ* states, localized in single nucleobases or delocalized over several of them. And on the other, excited charge transfer states in which an important fraction of an atomic charge has been transferred from one nucleobase to another. The latter are weakly emissive. And between these two types, there are emitting states more or less delocalized, with different amounts of charge transfer.[45]

The contribution of the nanosecond components to the duplex fluorescence increases with the local rigidity

A particular class of emitting states with mixed ππ*/charge transfer character was detected in all types of duplexes,[46] including genomic DNA.[47] Their particularity is that their fluorescence appears at short wavelengths (λ<330 nm) and it is long-lived, decaying within a few nanoseconds. Its contribution to the total fluorescence increases with the local rigidity of the duplex, depending on the number of the Watson-Crick hydrogen bonds or the size of the system.[48]

Applications

[edit]

The utilization of the intrinsic fluorescence of nucleic acids for sensing purposes started to be scrutinized just in 2019. The possibility of detecting target DNA[49] or Pb2+ ions,[50] the screening of a large number of sequences[51] or the authentication of COVID-19 vaccines[52] have been explored. Moreover, the possibility of detecting the DNA damage by probing its fluorescence at short wavelengths (300 nm) has been discussed.[53] Due to their modulable structure, G-quadruplexes, are particularly promising for the development of label-free and dye-free biosensors.[54][55]

Secondary sources

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Scientific reviews and accounts

[edit]
  • Improta, R.; Santoro, F.; Blancafort, L. (2016) Quantum Mechanical Studies on the Photophysics and the Photochemistry of Nucleic Acids and Nucleobases. Chemical Reviews, 116 (6), 3540-3593.[56]
  • Markovitsi, D. (2016) UV-induced DNA Damage: The Role of Electronic Excited States. Photochemistry and Photobiology-Invited Review. 92, 45-51.[57]
  • Gustavsson, T.; Markovitsi, D. (2021). Fundamentals of the Intrinsic DNA Fluorescence. Accounts of Chemical Research. 54 (5), 1226-1235. [58]
  • Martinez-Fernandez, L.; Santoro, F.; Improta, R. (2022) Nucleic Acids as a Playground for the Computational Study of the Photophysics and Photochemistry of Multichromophore Assemblies. Accounts of Chemical Research.55 (15), 2077-2087[59]
  • Markovitsi, D. (2024) Processes triggered in guanine quadruplexes by direct absorption of UV radiation: From fundamental studies toward optoelectronic biosensors. Photochemistry and Photobiology-Invited Review. 2024, 100 (2), 262–274[60]
  • Markovitsi, D. On the Use of the Intrinsic DNA Fluorescence for Monitoring its Damage - A Contribution from Fundamental Studies. ACS Omega (Review)[61]

Book chapters

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  • Markovitsi, D.; Gustavsson, T. Energy flow in DNA duplexes. In Energy Transfer Dynamics in Biomaterial Systems Burghardt, I., May, V., Micha, D. A., Bittner, E. R. Eds.; Springer Ser. Chem. Phys., Vol. 93; Springer, Heidelberg/Berlin, 2009; pp 127-142.[62]
  • Markovitsi, D.; Gustavsson, T.; Banyasz, A. DNA Fluorescence. In CRC Handbook of Organic Photochemistry and Photobiology, Chapter 42. Griesbeck, A., Ghetti, F., Oelgemoeller, M. Eds.; Taylor and Francis, 2012; pp 1057-1079 (ISBN: 9780429100253).[63]
  • Changenet-Barret, P.; Hua, Y.; Markovitsi, D. Electronic excitations in guanine quadruplexes. In Photoinduced Phenomena in Nucleic Acids II, Barbati, M., Borin, A. C., Ulrich, S. Eds.; Top. Curr. Chem., Vol. 356; Springer Nature, 2015; pp 183–202[64]
  • Martinez Fernandez, L.; Importa, R. Computational Studies on Photoinduced Charge Transfer Processes in Nucleic Acids: From Watson–Crick Dimers to Quadruple Helices. In Nucleic Acid Photophysics and Photochemistry, Matsika, S.; Marcus, A. H. Eds. Springer Nature, 2015; pp 27-50[65]

References

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  1. ^ Eisinger, J. (1966). "Excimer fluorescence of dinucleotides, polynucleotides and DNA". Proc. Natl. Acad. Sci. USA. 55 (5): 1015–1020. Bibcode:1966PNAS...55.1015E. doi:10.1073/pnas.55.5.1015. PMC 224269. PMID 5225506.
  2. ^ Peon, J. (2001). "DNA/RNA nucleotides and nucleosides: direct measurement of excited-state lifetimes by femtosecond fluorescence up-conversion". Chem. Phys. Lett. 348 (3–4): 255–262. Bibcode:2001CPL...348..255P. doi:10.1016/S0009-2614(01)01128-9.
  3. ^ Kwok, W-M. (2006). "Femtosecond time- and wavelength-resolved fluorescence and absorption study of the excited states of adenosine and an adenine oligomer". J. Am. Chem. Soc. 128 (36): 11894–12705. doi:10.1021/ja0622002. PMID 16953630.
  4. ^ Schwalb, N.K. (2008). "Base sequence and higher-order structure induce the complex excited-state dynamics in DNA". Science. 322 (5899): 243–245. Bibcode:2008Sci...322..243S. doi:10.1126/science.1161651. PMID 18845751.
  5. ^ Vaya, I. (2010). "Fluorescence of natural DNA: from the femtosecond to the nanosecond time-scales". J. Am. Chem. Soc. 132 (34): 11834–11835. Bibcode:2010JAChS.13211834V. doi:10.1021/ja102800r. PMID 20698570.
  6. ^ Wang, D.H. (2022). "Excited State Dynamics of Methylated Guanosine Derivatives Revealed by Femtosecond Time-resolved Spectroscopy". Photochem. Photobiol. 22 (5): 1008–1016. doi:10.1111/php.13612. PMID 35203108.
  7. ^ Gustavsson, T. (2023). "The Ubiquity of High-Energy Nanosecond Fluorescence in DNA Duplexes" (PDF). J. Phys. Chem. Lett. 14 (8): 2141–2147. doi:10.1021/acs.jpclett.2c03884. PMID 36802626.
  8. ^ Markovitsi, D. (2016). "UV-induced DNA Damage: The Role of Electronic Excited States". Photochem. Photobiol. 92 (1): 45–51. doi:10.1111/php.12533. PMID 26436855.
  9. ^ Yu, Z.W. (2024). "Ultraviolet (UV) radiation: a double-edged sword in cancer development and therapy". Molecular Biomedicine. 5 (1): 49. doi:10.1186/s43556-024-00209-8. PMC 11486887. PMID 39417901.
  10. ^ Xiang, X (2019). "Label-free and dye-free detection of target DNA based on intrinsic fluorescence of the (3+1) interlocked bimolecular G-quadruplexes". Sens. Actuators B Chem. 290 (290): 68–72. Bibcode:2019SeAcB.290...68X. doi:10.1016/j.snb.2019.03.111.
  11. ^ Lopez, A. (2022). "Probing metal-dependent G-quadruplexes using the intrinsic fluorescence of DNA". Chem. Comm. 58 (73): 10225–10228. doi:10.1039/d2cc03967b. PMID 36001027.
  12. ^ Markovitsi, D. (2006). "UVB/UVC induced processes in model DNA helices studied by time-resolved spectroscopy: pitfalls and tricks". J. Photochem. Photobiol. A-Chem. 183 (1–2): 1–8. Bibcode:2006JPPA..183....1M. doi:10.1016/j.jphotochem.2006.05.029.
  13. ^ Huix-Rotllant, M. (2015). "Stabilization of mixed Frenkel-charge transfer excitons extended across both strands of guanine-cytosine DNA duplexes". J. Phys. Chem. Lett. 6 (12): 3540–3593. doi:10.1021/acs.jpclett.5b00813. PMID 26266599.
  14. ^ Carroll, G.T. (2023). "Intrinsic fluorescence of UV-irradiated DNA". J. Photochem. Photobiol. A: Chem. 437: 114484. Bibcode:2023JPPA..43714484C. doi:10.1016/j.jphotochem.2022.114484.
  15. ^ Gustavsson; T. (2021). "Fundamentals of the Intrinsic DNA Fluorescence" (PDF). Acc. Chem. Res. 54 (5): 1226–1235. doi:10.1021/acs.accounts.0c00603. PMID 33587613.
  16. ^ Mouret, S. (2010). "UVA-induced cyclobutane pyrimidine dimers in DNA: a direct photochemical mechanism?" (PDF). Org. Biomol. Chem. 8 (7): 1706–1711. doi:10.1039/b924712b. PMID 20237685.
  17. ^ Banyasz, A. (2011). "Base-pairing enhances fluorescence and favors cyclobutane dimer formation induced upon absorption of UVA radiation by DNA" (PDF). J. Am. Chem. Soc. 133 (14): 5163–5165. Bibcode:2011JAChS.133.5163B. doi:10.1021/ja110879m. PMID 21417388.
  18. ^ Spata, V.A. (2016). "Excimers and Exciplexes in Photoinitiated Processes of Oligonucleotides". J. Chem. Phys. Lett. 7 (6): 976–984. doi:10.1021/acs.jpclett.5b02756. PMID 26911276.
  19. ^ Martinez-Fernandez, L. (2022). "Nucleic Acids as a Playground for the Computational Study of the Photophysics and Photochemistry of Multichromophore Assemblies". Acc. Chem. Res. 55 (15): 2077–2087. doi:10.1021/acs.accounts.2c00256. PMID 35833758.
  20. ^ Gustavsson; T. (2021). "Fundamentals of the Intrinsic DNA Fluorescence" (PDF). Acc. Chem. Res. 54 (5): 1226–1235. doi:10.1021/acs.accounts.0c00603. PMID 33587613.
  21. ^ Dao, N.T. (2011). "Following G-quadruplex formation by its intrinsic fluorescence". FEBS Letters. 585 (24): 3969–3977. Bibcode:2011FEBSL.585.3969D. doi:10.1016/j.febslet.2011.11.004. hdl:10356/98618. PMID 22079665.
  22. ^ Ma, M.S. (2019). "Real-time Monitoring Excitation Dynamics of Human Telomeric Guanine Quadruplexes: Effect of Folding Topology, Metal Cation, and Confinement by Nanocavity Water Pool". J. Phys. Chem. Lett. 10 (24): 7577–7585. doi:10.1021/acs.jpclett.9b02932. PMID 31769690.
  23. ^ Markovitsi, D. (2024). "10.1021/acsomega.4c02256". ACS Omega. 9 (25): 26826–26837. doi:10.1021/acsomega.4c02256. PMC 11209687. PMID 38947837.
  24. ^ Dao, N.T. (2011). "Following G-quadruplex formation by its intrinsic fluorescence". FEBS Letters. 585 (24): 3969–3977. Bibcode:2011FEBSL.585.3969D. doi:10.1016/j.febslet.2011.11.004. hdl:10356/98618. PMID 22079665.
  25. ^ Markovitsi, D. (2004). "Cooperative effects in the photophysical properties of self-associated triguanosine diphosphates". Photochem. Photobiol. 79 (6): 526–530. doi:10.1562/2003-12-12-RA.1 (inactive 28 December 2024). PMID 15291304.{{cite journal}}: CS1 maint: DOI inactive as of December 2024 (link)
  26. ^ Feng, H. (2022). "Spectroscopic analysis reveals the effect of hairpin loop formation on G-quadruplex structures". RSC Chem. Biol. 3 (4): 431–435. doi:10.1039/d2cb00045h. PMC 8984947. PMID 35441140.
  27. ^ Morshedi, M. (2024). "References for Small Fluorescence Quantum Yields". Journal of Fluorescence. doi:10.1007/s10895-024-03729-2. PMID 38748338.
  28. ^ Peon, J. (2001). "DNA/RNA nucleotides and nucleosides: direct measurement of excited-state lifetimes by femtosecond fluorescence up-conversion". Chem. Phys. Lett. 348 (3–4): 255–262. Bibcode:2001CPL...348..255P. doi:10.1016/S0009-2614(01)01128-9.
  29. ^ Schwalb, N.K. (2008). "Base sequence and higher-order structure induce the complex excited-state dynamics in DNA". Science. 322 (5899): 243–245. Bibcode:2008Sci...322..243S. doi:10.1126/science.1161651. PMID 18845751.
  30. ^ Vaya, I. (2010). "Fluorescence of natural DNA: from the femtosecond to the nanosecond time-scales". J. Am. Chem. Soc. 132 (34): 11834–11835. Bibcode:2010JAChS.13211834V. doi:10.1021/ja102800r. PMID 20698570.
  31. ^ Kwok, W.-M. (2006). "Femtosecond time- and wavelength-resolved fluorescence and absorption study of the excited states of adenosine and an adenine oligomer". J. Am. Chem. Soc. 128 (36): 11894–11905. doi:10.1021/ja0622002. PMID 16953630.
  32. ^ Vaya, I. (2016). "High energy long-lived mixed Frenkel – charge transfer excitons: from double-stranded (AT)n to natural DNA". Chem. Eur. J. 22 (14): 4904–4914. doi:10.1002/chem.201504007. PMID 26928984.
  33. ^ Hua, Y (2012). "Cation Effect on the Electronic Excited States of Guanine Nanostructures Studied by Time-Resolved Fluorescence Spectroscopy". J. Phys. Chem. C. 116 (27): 14682–14689. doi:10.1021/jp303651e.
  34. ^ Ma, M.S. (2019). "Real-time Monitoring Excitation Dynamics of Human Telomeric Guanine Quadruplexes: Effect of Folding Topology, Metal Cation, and Confinement by Nanocavity Water Pool". J. Phys. Chem. Lett. 10 (24): 7577–7585. doi:10.1021/acs.jpclett.9b02932. PMID 31769690.
  35. ^ Improta, R. (2016). "Quantum Mechanical Studies on the Photophysics and the Photochemistry of Nucleic Acids and Nucleobases". Chem. Rev. 116 (6): 3540–3593. doi:10.1021/acs.chemrev.5b00444. PMID 26928320.
  36. ^ Onidas, D. (2002). "Fluorescence properties of DNA nucleosides and nucleotides: a refined steady-state and femtosecond investigation". J. Phys. Chem. B. 106 (43): 11367–11374. doi:10.1021/jp026063g.
  37. ^ Pancur, T. (2005). "Femtosecond fluorescence up-conversion spectroscopy of adenine and adenosine: experimental evidence for the ps* state?". Chem. Phys. 313: 199–212. doi:10.1016/j.chemphys.2004.12.019.
  38. ^ Kwok, M.-W. (2008). "A doorway state leads to photostability or triplet photodamage in thymine DNA". J. Am. Chem. Soc. 130 (15): 5131–5139. Bibcode:2008JAChS.130.5131K. doi:10.1021/ja077831q. PMID 18335986.
  39. ^ Gustavsson, T. (2010). "DNA/RNA: Building Blocks of Life Under UV Irradiation" (PDF). J. Phys. Chem. Lett. 1 (13): 2025–2030. doi:10.1021/jz1004973.
  40. ^ Bouvier, B. (2002). "Dipolar coupling between electronic transitions of the DNA bases and its relevance to exciton states in double helices". Chem. Phys. 275 (1–3): 75–92. Bibcode:2002CP....275...75B. doi:10.1016/S0301-0104(01)00523-7.
  41. ^ Plasser, F. (2015). "lectronic Excitation Processes in Single-Strand and Double-Strand DNA: A Computational Approach". Top. Curr. Chem. Topics in Current Chemistry. 356: 1–38. doi:10.1007/128_2013_517. ISBN 978-3-319-13271-6. PMID 24549841.
  42. ^ Blancafort, L. (2014). "Exciton delocalization, charge transfer, and electronic coupling for singlet excitation energy transfer between stacked nucleobases in DNA: An MS-CASPT2 study". J. Chem. Phys. 140 (9). Bibcode:2014JChPh.140i5102B. doi:10.1063/1.4867118. hdl:10256/11471. PMID 24606381.
  43. ^ Martínez Fernández, Lara; Santoro, Fabrizio; Improta, Roberto (2022). "Nucleic Acids as a Playground for the Computational Study of the Photophysics and Photochemistry of Multichromophore Assemblies". Accounts of Chemical Research. 55 (15): 2077–2087. doi:10.1021/acs.accounts.2c00256. PMID 35833758.
  44. ^ Bouvier, B. (2003). "Influence of conformational dynamics on the exciton states of DNA oligomers". J. Phys. Chem. B. 107 (48): 13512–13522. doi:10.1021/jp036164u.
  45. ^ Gustavsson, Thomas; Markovitsi, Dimitra (2021). "Fundamentals of the Intrinsic DNA Fluorescence". Accounts of Chemical Research. 54 (5): 1226–1235. doi:10.1021/acs.accounts.0c00603. PMID 33587613.
  46. ^ Vaya, I (2010). "High energy long-lived excited states in DNA double strands" (PDF). ChemPhysChem. 11 (5): 987–989. doi:10.1002/cphc.201000027. PMID 20217890.
  47. ^ Vaya, I. (2016). "High energy long-lived mixed Frenkel – charge transfer excitons: from double-stranded (AT)n to natural DNA". Chem. Eur. J. 22 (14): 4904–4914. doi:10.1002/chem.201504007. PMID 26928984.
  48. ^ Gustavsson, T. (2023). "The Ubiquity of High-Energy Nanosecond Fluorescence in DNA Duplexes" (PDF). J. Phys. Chem. Lett. 14 (8): 2141–2147. doi:10.1021/acs.jpclett.2c03884. PMID 36802626.
  49. ^ Xiang, X (2019). "Label-free and dye-free detection of target DNA based on intrinsic fluorescence of the (3+1) interlocked bimolecular G-quadruplexes". Sens. Actuators B Chem. 290 (290): 68–72. Bibcode:2019SeAcB.290...68X. doi:10.1016/j.snb.2019.03.111.
  50. ^ Lopez, A. (2022). "Probing metal-dependent G-quadruplexes using the intrinsic fluorescence of DNA". Chem. Comm. 58 (73): 10225–10228. doi:10.1039/d2cc03967b. PMID 36001027.
  51. ^ Zuffo, M. (2020). "Harnessing intrinsic fluorescence for typing of secondary structures of DNA". Nucl. AC. Res. 48 (11): e61. doi:10.1093/nar/gkaa257. PMC 7293009. PMID 32313962.
  52. ^ Assi, S. (2023). "Authentication of Covid-19 Vaccines Using Synchronous Fluorescence Spectroscopy". J. Fluoresc. 33 (3): 1165–1174. doi:10.1007/s10895-022-03136-5. PMC 9825072. PMID 36609659.
  53. ^ Markovitsi, D. (2024). "10.1021/acsomega.4c02256". ACS Omega. 9 (25): 26826–26837. doi:10.1021/acsomega.4c02256. PMC 11209687. PMID 38947837.
  54. ^ Lu, C. (2022). "Using the Intrinsic Fluorescence of DNA to Characterize Aptamer Binding". Molecules. 27 (22): 7809. doi:10.3390/molecules27227809. PMC 9692703. PMID 36431910.
  55. ^ Markovitsi, D. (2024). "Processes triggered in guanine quadruplexes by direct absorption of UV radiation: From fundamental studies toward optoelectronic biosensors". Photochem. Photobiol. 100 (2): 262–274. doi:10.1111/php.13826. PMID 37365765.
  56. ^ Improta, Roberto; Santoro, Fabrizio; Blancafort, Lluís (2016). "Quantum Mechanical Studies on the Photophysics and the Photochemistry of Nucleic Acids and Nucleobases". Chemical Reviews. 116 (6): 3540–3593. doi:10.1021/acs.chemrev.5b00444. PMID 26928320.
  57. ^ Markovitsi, Dimitra (2016). "UV-inducedDNADamage: The Role of Electronic Excited States". Photochemistry and Photobiology. 92 (1): 45–51. doi:10.1111/php.12533. PMID 26436855.
  58. ^ Gustavsson, Thomas; Markovitsi, Dimitra (2021). "Fundamentals of the Intrinsic DNA Fluorescence". Accounts of Chemical Research. 54 (5): 1226–1235. doi:10.1021/acs.accounts.0c00603. PMID 33587613.
  59. ^ Martínez Fernández, Lara; Santoro, Fabrizio; Improta, Roberto (2022). "Nucleic Acids as a Playground for the Computational Study of the Photophysics and Photochemistry of Multichromophore Assemblies". Accounts of Chemical Research. 55 (15): 2077–2087. doi:10.1021/acs.accounts.2c00256. PMID 35833758.
  60. ^ Markovitsi, Dimitra (2024). "Processes triggered in guanine quadruplexes by direct absorption of UV radiation: From fundamental studies toward optoelectronic biosensors". Photochemistry and Photobiology. 100 (2): 262–274. doi:10.1111/php.13826. PMID 37365765.
  61. ^ Markovitsi, Dimitra (2024). "On the Use of the Intrinsic DNA Fluorescence for Monitoring Its Damage: A Contribution from Fundamental Studies". ACS Omega. 9 (25): 26826–26837. doi:10.1021/acsomega.4c02256. PMC 11209687. PMID 38947837.
  62. ^ Markovitsi, Dimitra; Gustavsson, Thomas (2009). "Energy Flow in DNA Duplexes". Energy Transfer Dynamics in Biomaterial Systems. Springer Series in Chemical Physics. Vol. 93. pp. 127–142. doi:10.1007/978-3-642-02306-4_5. ISBN 978-3-642-02305-7.
  63. ^ Griesbeck, Axel; Oelgemöller, Michael; Ghetti, Francesco (2019). CRC Handbook of Organic Photochemistry and Photobiology, Third Edition - Two Volume Set. doi:10.1201/9780429100253. ISBN 978-0-429-10025-3.
  64. ^ https://link.springer.com/chapter/10.1007/128_2013_5111
  65. ^ Fernández, Lara Martínez; Improta, Roberto (2024). "Computational Studies on Photoinduced Charge Transfer Processes in Nucleic Acids: From Watson–Crick Dimers to Quadruple Helices". Nucleic Acid Photophysics and Photochemistry. Nucleic Acids and Molecular Biology. Vol. 36. pp. 29–50. doi:10.1007/978-3-031-68807-2_2. ISBN 978-3-031-68806-5.
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