Effect of solvent on nanoscale polymer heterogeneity and mobility probed by single molecule lifetime fluctuations

Vallée, Renaud A. L.; Tomczak, Nikodem; Kuipers, L.; Vancso, Gyula J.; Hulst, Niek F. van

doi:10.1016/j.cplett.2003.11.086

Cited by 11 publications

(6 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For molecules with near unity quantum yields under varying conditions, the fluctuating dielectric of the medium surrounding single dye molecules can effectively be probed. , For OPV molecules, it is possible that changes in the polarizability of the surroundings yield changes in the emissive quantum yield (often measured as the single dye molecule radiative lifetime: τ ≈ k F -1 ), but here we are more concerned with the long-lived environment-induced changes seen in the intensity trajectories. Because the OPV molecules do not have a permanent dipole moment or exhibit a charge-transfer spectrum, differences in polarity among the environments studied are not expected to play as significant a role on the SM photophysics as seen for other polar single molecules. ,− Instead, we postulate that the fluctuations we see are linked to the viscoelastic properties of the surroundings, which are related to the longer time scale motions of the atoms and bonds of the matrix and which determine how much freedom of motion is afforded to the OPV single molecules. Single molecule dynamics caused by photoisomerization have previously been observed for the well-studied “Cy5” cyanine dye in fluid solution, where solvent viscosity was linked to photoisomerization .…”

Section: Discussionmentioning

confidence: 85%

“…Single fluorescent molecules are sensitive probes of their surroundings. , Data extracted from SM experiments including fluorescence intensity trajectories, spectral shape and position, and fluorescence lifetimes can be used to investigate the chemical and physical characteristics of the surrounding medium. For example, recent work has demonstrated that the charge-transfer spectra of single dye molecules are very sensitive to the polarizability of their surroundings and enable nanoscale characterization of thin polymer films. − Recent experimental and theoretical reports have demonstrated how a fluctuating dielectric nanoenvironment surrounding a polarizable probe molecule gives rise to a distribution of measured fluorescence lifetimes. , Single molecule experiments can also help to predict how the physical environment surrounding molecules will affect their emissive properties. Single molecules embedded in polymer matrixes near their glass-transition temperature have been used to characterize the physics of polymers undergoing phase transitions. , Single molecule photophysics reveal that the conformations adopted by isolated conjugated polymers in polystyrene matrixes vary according to the average molecular weight of the polystyrene used .…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Matrix-Induced Intensity Fluctuations in the Fluorescence from Single Oligo(phenylenevinylene) Molecules

2005

View full text Add to dashboard Cite

Single molecule spectroscopy on oligo(phenylenevinylene) (OPV) chromophores shows that the fluorescence intermittency strongly correlates to the rigidity of the environment surrounding the molecules. For OPV single molecules, environmental rigidity inhibits twisting about the vinyl linkages, the molecular motion associated with the observed "off" (nonabsorbing) state. By increasing the rigidity of a single molecule's environment, we can tune its room temperature fluorescence from rapid, sub-millisecond "blinking" fluctuations (fluid polymer environment) to completely "on" with no blinking observed (molecules adsorbed to a rigid bare glass substrate). The difference in fluorescence intermittency from environment to environment is immediately apparent and explicit in single molecule intensity trajectories under cw (continuous wave) excitation, demonstrating the sensitivity of these chromophores to their surroundings and emphasizing the importance of morphological control in real-world applications involving phenylenevinylene-based materials.

show abstract

Section: Discussionmentioning

confidence: 85%

Section: Introductionmentioning

confidence: 99%

Matrix-Induced Intensity Fluctuations in the Fluorescence from Single Oligo(phenylenevinylene) Molecules

2005

View full text Add to dashboard Cite

show abstract

“…SM observables in this class that have been followed to study polymers both above and below T g include blinking (39,(107)(108)(109)(110) and emission spectra (111,112), both of which may change as a function of environmental rigidity. The most commonly tracked observable in this class is FL, and FL measurements have been applied broadly to study polymeric systems both below T g (97,(113)(114)(115)(116)(117)(118)(119)(120) and above T g (69,74,97,116,121,122), but to date they have not been applied to the study of small-molecule supercooled liquids.…”

Section: Measurements Of Fluorescence Lifetimementioning

confidence: 99%

Heterogeneity in Single-Molecule Observables in the Study of Supercooled Liquids

Kaufman

2013

Annu. Rev. Phys. Chem.

View full text Add to dashboard Cite

Bulk approaches to studying heterogeneous systems obscure important details, as they report average behavior rather than the distribution of behaviors in such environments. Small-molecule and polymeric supercooled liquids, which display heterogeneity in their dynamics without an underlying structural heterogeneity that sets those dynamics, are important constituents of this category of condensed matter systems. A variety of approaches have been devised to unravel ensemble averaging in supercooled liquids. This review focuses on the ultimate subensemble approach, single-molecule measurements, as they have been applied to the study of supercooled liquids. We detail how three key experimental observables (single-molecule probe rotation, translation, and fluorescence lifetime) have been employed to provide detail on dynamic heterogeneity in supercooled liquids. Special attention is given to the potential for, but also the challenges in, discriminating spatial and temporal heterogeneity and detailing the length scales and timescales of heterogeneity in these systems.

show abstract

“…Spectral diffusion of a chromophore has been interpreted as due to transitions of the molecule between different chromophore conformations (27) or in terms of the density fluctuations of the dielectric matrix leading to polarization fluctuations (28). Previous studies of a different nature have included the role of the electric field on time-dependent vibrational Stark shift at the heme site of myoglobin (29) and of the nitrile stretching mode in human aldose reductase (30), both in the picosecond regime.…”

Section: ؊1mentioning

confidence: 99%

An interpretation of fluctuations in enzyme catalysis rate, spectral diffusion, and radiative component of lifetimes in terms of electric field fluctuations

Prakash

Marcus

2007

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Time-dependent fluctuations in the catalysis rate (␦k(t)) observed in single-enzyme experiments were found in a particular study to have an autocorrelation function decaying on the same time scale as that of spectral diffusion ␦0(t). To interpret this similarity, the present analysis focuses on a factor in enzyme catalysis, the local electrostatic interaction energy (E) at the active site and its effect on the activation free energy barrier. We consider the slow fluctuations of the electrostatic interaction energy (␦E(t)) as a contributor to ␦k(t) and relate the latter to ␦0(t). The resulting relation between ␦k(t) and ␦0(t) is a dynamic analog of the solvatochromism used in interpreting solvent effects on organic reaction rates. The effect of the postulated ␦E(t) on fluctuations in the radiative component (␦␥ r ؊1(t)) of the fluorescence decay of chromophores in proteins also is examined, and a relation between ␦␥ r ؊1 (t) and ␦0(t) is obtained. Experimental tests will determine whether the correlation functions for ␦k(t), ␦0(t), and ␦␥ r ؊1 are indeed similar for any enzyme. Measurements of dielectric dispersion, (), for the enzyme discussed elsewhere will provide further insight into the correlation function for ␦E(t). They also will determine whether fluctuations in the nonradiative component ␥ nr ؊1 of the lifetime decay has a different origin, fluctuations in distance for example.fluorescence ͉ single enzyme S ingle-molecule experiments on proteins have revealed novel phenomena, including fluctuations in the rates of enzyme catalysis (1-3), on-off blinking behavior in proteins (4-6), and oscillations under a near-denatured condition of a green fluorescent protein (7). The on-off blinking behavior of proteins and the fluctuations in the enzyme catalysis rate in the experiments were interpreted in terms of fluctuations of the protein/enzyme between various conformational substates (2, 3). The rates of enzyme-catalyzed reactions themselves occur typically on the milliseconds-to-seconds time scale, and the millisecond dynamics of enzymes are believed to contribute to the ''functional dynamics'' of the enzyme (8). Single-molecule enzyme experiments on cholesterol oxidase revealed an autocorrelation function of the rate of catalysis that decayed on a time scale about the same as that for the decay of the autocorrelation function of the spectral diffusion of a chromophore in the same enzyme in the absence of the substrate (1), thus suggesting a common origin for the two fluctuations.Significant insight into the functioning of enzymes has been achieved by using computer simulations (9-11) and empirical valence bond (9) and hybrid quantum mechanical/molecular mechanics (10) methods, among others. In these studies the catalysis is affected by several factors: electrostatic effects of the enzyme on the substrate (9) and coupling of protein fluctuations with motions of the substrate-coenzyme pair in the transition state (e.g., ref. 8). Electrostatic effects have been seen to be significant in enzymatic catalysis (9,(1...

show abstract

Effect of solvent on nanoscale polymer heterogeneity and mobility probed by single molecule lifetime fluctuations

Cited by 11 publications

References 27 publications

Matrix-Induced Intensity Fluctuations in the Fluorescence from Single Oligo(phenylenevinylene) Molecules

Matrix-Induced Intensity Fluctuations in the Fluorescence from Single Oligo(phenylenevinylene) Molecules

Heterogeneity in Single-Molecule Observables in the Study of Supercooled Liquids

An interpretation of fluctuations in enzyme catalysis rate, spectral diffusion, and radiative component of lifetimes in terms of electric field fluctuations

Contact Info

Product

Resources

About