Decreasing photobleaching by silver nanoparticles on metal surfaces: application to muscle myofibrils

Muthu, Priya; Gryczyński, Ignacy; Gryczyński, Zygmunt; Talent, John M.; Akopova, Irina; Borejdo, Julian

doi:10.1117/1.2854120

Cited by 9 publications

(12 citation statements)

References 27 publications

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“…The lifetimes of free and bound RP in water and glycerol were measured with/in a FluoTime 200 fluorometer (PicoQuant Inc) equipped with a microchannel plate (MCP) and 470 nm pulsed laser diode (76 psec half-width). This instrument provides an exceptional resolution in the sub-nanosecond range [46]. …”

Section: Methodsmentioning

confidence: 99%

Single molecule kinetics in the familial hypertrophic cardiomyopathy D166V mutant mouse heart

Muthu

Mettikolla

Calander

et al. 2010

Journal of Molecular and Cellular Cardiology

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One of the sarcomeric mutations associated with a malignant phenotype of Familial Hypertrophic Cardiomyopathy (FHC) is the D166V point mutation in the ventricular myosin regulatory light chain (RLC) encoded by the MYL2 gene. In this report we show that the rates of myosin cross-bridge attachment and dissociation are significantly different in isometrically contracting cardiac myofibrils from right ventricles of transgenic (Tg)-D166V and Tg-WT mice. We have derived the myosin crossbridge kinetic rates by tracking the orientation of a fluorescently labeled single actin molecule. Orientation (measured by polarized fluorescence) oscillated between two states, corresponding to the actin-bound and actin-free states of the myosin cross-bridge. The rate of cross-bridge attachment during isometric contraction decreased from 3 s −1 in myofibrils from Tg-WT to1.4 s −1 in myofibrils from Tg-D166V. The rate of detachment decreased from 1.3 s −1 (Tg-WT) to 1.2 s −1 (Tg-D166V). We also showed that the level of RLC phosphorylation was largely decreased in Tg-D166V myofibrils compared to Tg-WT. Our findings suggest that alterations in the myosin cross-bridge kinetics brought about by the D166V mutation in RLC might be responsible for the compromised function of the mutated hearts and lead to their inability to efficiently pump blood.

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Section: Methodsmentioning

confidence: 99%

Single molecule kinetics in the familial hypertrophic cardiomyopathy D166V mutant mouse heart

Muthu

Mettikolla

Calander

et al. 2010

Journal of Molecular and Cellular Cardiology

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“…We previously observed increased photostability of fluorophores deposited on silver nanoparticels [23–27]. Both, decrease in the fluorescence lifetime and increase in the quantum yield lead to a significant reduction of photodegradation.…”

Section: Resultsmentioning

confidence: 99%

Metal enhanced fluorescence on silicon wafer substrates

Gryczyński¹,

Matveeva²,

Sarkar³

et al. 2008

Chemical Physics Letters

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We report on the fluorescence enhancement induced by silver island film (SIF) deposited on a silicon wafer. The model immunoassay was studied on silvered and unsilvered wafers. The fluorescence brightness of Rhodamine Red X increased about 300% on the SIF, while the lifetime was reduced by several fold and the photostability increased substantially. We discuss potential uses of silicon wafer substrates in multiplex assays in which the fluorescence is enhanced due to the SIF, and the multiplexing is achieved by using micro transponders.

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“…Nanoparticles and myofibrils are deposited on a glass coverslip. The Z-dimension of nanoparticles is comparable to the size of the myofibrils (23). We assume that nanoparticles are spheroid.…”

Section: Discussionmentioning

confidence: 99%

Monolayers of Silver Nanoparticles Decrease Photobleaching: Application to Muscle Myofibrils

Muthu

Calander

Gryczyński

et al. 2008

Biophysical Journal

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Studying single molecules in a cell has the essential advantage that kinetic information is not averaged out. However, since fluorescence is faint, such studies require that the sample be illuminated with the intense light beam. This causes photodamage of labeled proteins and rapid photobleaching of the fluorophores. Here, we show that a substantial reduction of these types of photodamage can be achieved by imaging samples on coverslips coated with monolayers of silver nanoparticles. The mechanism responsible for this effect is the interaction of localized surface plasmon polaritons excited in the metallic nanoparticles with the transition dipoles of fluorophores of a sample. This leads to a significant enhancement of fluorescence and a decrease of fluorescence lifetime of a fluorophore. Enhancement of fluorescence leads to the reduction of photodamage, because the sample can be illuminated with a dim light, and decrease of fluorescence lifetime leads to reduction of photobleaching because the fluorophore spends less time in the excited state, where it is susceptible to oxygen attack. Fluorescence enhancement and reduction of photobleaching on rough metallic surfaces are usually accompanied by a loss of optical resolution due to refraction of light by particles. In the case of monolayers of silver nanoparticles, however, the surface is smooth and glossy. The fluorescence enhancement and the reduction of photobleaching are achieved without sacrificing the optical resolution of a microscope. Skeletal muscle myofibrils were used as an example, because they contain submicron structures conveniently used to define optical resolution. Small nanoparticles (diameter approximately 60 nm) did not cause loss of optical resolution, and they enhanced fluorescence approximately 500-fold and caused the appearance of a major picosecond component of lifetime decay. As a result, the sample photobleached approximately 20-fold more slowly than the sample on glass coverslips.

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Decreasing photobleaching by silver nanoparticles on metal surfaces: application to muscle myofibrils

Cited by 9 publications

References 27 publications

Single molecule kinetics in the familial hypertrophic cardiomyopathy D166V mutant mouse heart

Single molecule kinetics in the familial hypertrophic cardiomyopathy D166V mutant mouse heart

Metal enhanced fluorescence on silicon wafer substrates

Monolayers of Silver Nanoparticles Decrease Photobleaching: Application to Muscle Myofibrils

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