Improvements in the Generation of Quasi-Continuous, Tunable Ultraviolet Excitation for Raman Spectroscopy: Applications to Drug/Nucleotide Interactions

Benson, Ronda L.; Iwata, Koichi; Weaver, W. R.; Gustafson, Terry L.

doi:10.1366/0003702924125591

Cited by 15 publications

(3 citation statements)

References 32 publications

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“…Gustafson and co-workers demonstrated the generation of quasi-CW ultraviolet excitation below than 240 nm using the frequency-doubled output of a synchronously pum ped MHz picosecond dye laser operating in the 420 nm region. 12 Recently, Doig and Prendergast developed a continuously tunable source via tripling or quadrupling a mode-locked ; 2 ps Ti : sapphire (Ti : S) laser, which has a high duty cycle and good tunability. 13 However, the laser linewidth is about 10 ±15 cm 2 1 , which is too broad for m any UVRR applications.…”

Section: Introductionmentioning

confidence: 99%

Solid-State Tunable kHz Ultraviolet Laser for Raman Applications

et al. 1999

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Performance characteristics are described for a kilohertz solid-state laser source for resonance Raman spectroscopy. Narrow line excitation in the 205–230 nm region is provided by quadrupling a titanium: sapphire laser which is pumped by the second harmonic of a Q-switched YLF laser. The combination of tunability, narrow line, high average power, and good stability makes this laser suitable for ultraviolet resonance Raman (UVRR) applications. UVRR spectra of hemoglobin, excited at 229 nm, are as high in quality as those produced by continuous-wave intracavity frequency-doubled Ar+ laser excitation. Raman excitation profiles are reported for aromatic acids in aqueous solution and in hemoglobin.

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Section: Introductionmentioning

confidence: 99%

Solid-State Tunable kHz Ultraviolet Laser for Raman Applications

et al. 1999

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“…Excitation in the deep UV is particularly important because resonance with amide -* transitions enhances amide backbone vibrations that are sensitive probes of protein secondary structures. [5][6][7][8][9][10] Earlier deep UV lasers were based on harmonic generation of dye lasers, or of the Nd-YAG laser, with Raman shifting in H 2 , D 2 , or CH 4 gases. The frequency doubled outputs of continuous wave (CW) Ar ϩ , Kr ϩ , and hollow cathode lasers have also been used.…”

Section: Introductionmentioning

confidence: 99%

Tunable kHz Deep Ultraviolet (193–210 nm) Laser for Raman Applications

Balakrishnan

Nielsen

et al. 2005

Appl Spectrosc

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The performance characteristics of a kilohertz solid-state laser source for ultraviolet Raman spectroscopy are described. Deep ultraviolet (UV) excitation in the 193-210 nm region is provided by mixing of the fundamental and third harmonics of a Ti-sapphire laser, which is pumped by the second harmonic of a Q-Switched Nd-YLF laser. The combination of tunability, narrow linewidth, high average power, good stability, and kilohertz repetition rate makes this laser suitable for deep UV resonance Raman applications. The short pulse duration (approximately 20 ns) permits nanosecond time resolution in pump-probe applications. The low peak power and high data rate provide artifact-free spectra with a high signal-to-noise ratio. UV Raman cross-section and Raman excitation profiles are reported for gaseous O2 (relative to N), aqueous ClO4-, tyrosine, phenylalanine, tryptophan, histidine, and hemoglobin excited between 193 nm and 210 nm to illustrate laser performance.

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“…The vibrational modes in established intercalators such as pyrene and daunomycin, well-known groove binders such as netropsin, covalent binders such as cis -platin, , as well as nucleic acids themselves , have been measured by infrared absorption and Raman (resonant and nonresonant) scattering using ultraviolet excitation. These studies have shown that significant changes in the vibrational degrees of freedom in both the binding drug and DNA occur when the two are combined.…”

Section: Introductionmentioning

confidence: 99%

Picosecond Coherent Vibrational Spectroscopy (CARS) of a DNA-Intercalating Ru Complex

Ujj¹,

Coates²,

Kelly³

et al. 2002

J. Phys. Chem. B

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Vibrational spectra (1100−1800 cm-1) of the ground state and two excited electronic states, populated following the 5 ps, 440 nm excitation, of the [Ru(phen)2dppz]+2 (phen = 1,10-phenanthroline and dppz = dipyrido[3,2-a:2‘,3‘-c] phenazine) complex in aqueous solution are measured by coherent anti-Stokes Raman scattering (CARS). The band origin positions of vibrational features in the picosecond resonance CARS (PR/CARS) spectrum of ground state [Ru(phen)2dppz]+2 obtained with ω1 (probe) wavelengths of 491 and 530 nm are the same to within <1 cm-1 and correlate well with 488 nm resonance Raman data. The relative intensities of features in the 491 and 530 nm CARS spectra, however, are significantly different, reflecting the differences in Raman resonance enhancement associated with changes in excitation wavelengths. High signal-to-noise vibrational CARS spectra of samples containing [Ru(phen)2dppz]+2 and calf thymus DNA are also recorded using 491 and 530 nm ω1 excitation. Relative to CARS data from [Ru(phen)2dppz]2+ alone, small, but well-defined, shifts in band origin positions and large relative intensity changes are present. These changes are discussed in relation to possible structural changes in [Ru(phen)2dppz]2+ attributable to its interactions with DNA. Picosecond transient absorption (PTA) signals, recorded over the initial 4.0 ns interval after 440 nm, 5 ps excitation and using five probe wavelengths in the 500−560 nm range, confirm the presence of two photophysical intermediates that have previously been assigned as metal−ligand charge transfer (MLCT) excited states (i.e., MLCT(1) and MLCT(2)). Picosecond time-resolved CARS (PTR/CARS) spectra (ω1 = 530 nm) of [Ru(phen)2dppz]2+ in water, recorded at 23, 30, 100, 200, and 700 ps delays, provide five independent measurements of the MLCT(2) vibrational spectrum. Although the vibrational CARS features (positions and relative intensities) assigned to MLCT(2) remain the same throughout its 260 ps lifetime, the changes in their absolute intensities correlate closely with the PTA signals, thereby indicating that MLCT(2) has a well-defined and stable structure throughout and that little, if any, vibrational redistribution occurs during its 260 ps lifetime. The vibrational spectrum of another intermediate, not assignable to either ground state [Ru(phen)2dppz]2+ or its MLCT(2) state, is found in the 15 ps PTR/CARS data. Candidates for the assignment of this second intermediate, including MLCT(1), are discussed.

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Improvements in the Generation of Quasi-Continuous, Tunable Ultraviolet Excitation for Raman Spectroscopy: Applications to Drug/Nucleotide Interactions

Cited by 15 publications

References 32 publications

Solid-State Tunable kHz Ultraviolet Laser for Raman Applications

Solid-State Tunable kHz Ultraviolet Laser for Raman Applications

Tunable kHz Deep Ultraviolet (193–210 nm) Laser for Raman Applications

Picosecond Coherent Vibrational Spectroscopy (CARS) of a DNA-Intercalating Ru Complex

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