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Förster Resonance Energy Transfer between Core/Shell Quantum Dots and Bacteriorhodopsin.

Griep MH, Winder EM, Lueking DR, Garrett GA, Karna SP, Friedrich CR - Mol Biol Int (2012)

Bottom Line: An energy transfer relationship between core-shell CdSe/ZnS quantum dots (QDs) and the optical protein bacteriorhodopsin (bR) is shown, demonstrating a distance-dependent energy transfer with 88.2% and 51.1% of the QD energy being transferred to the bR monomer at separation distances of 3.5 nm and 8.5 nm, respectively.Fluorescence lifetime measurements isolate nonradiative energy transfer, other than optical absorptive mechanisms, with the effective QD excited state lifetime reducing from 18.0 ns to 13.3 ns with bR integration, demonstrating the Förster resonance energy transfer contributes to 26.1% of the transferred QD energy at the 3.5 nm separation distance.The established direct energy transfer mechanism holds the potential to enhance the bR spectral range and sensitivity of energies that the protein can utilize, increasing its subsequent photocurrent generation, a significant potential expansion of the applicability of bR in solar cell, biosensing, biocomputing, optoelectronic, and imaging technologies.

View Article: PubMed Central - PubMed

Affiliation: Department of Mechanical Engineering Mechanics, Michigan Technological University, 815 RL Smith, 1400 Townsend Drive, Houghton, MI 49931, USA.

ABSTRACT
An energy transfer relationship between core-shell CdSe/ZnS quantum dots (QDs) and the optical protein bacteriorhodopsin (bR) is shown, demonstrating a distance-dependent energy transfer with 88.2% and 51.1% of the QD energy being transferred to the bR monomer at separation distances of 3.5 nm and 8.5 nm, respectively. Fluorescence lifetime measurements isolate nonradiative energy transfer, other than optical absorptive mechanisms, with the effective QD excited state lifetime reducing from 18.0 ns to 13.3 ns with bR integration, demonstrating the Förster resonance energy transfer contributes to 26.1% of the transferred QD energy at the 3.5 nm separation distance. The established direct energy transfer mechanism holds the potential to enhance the bR spectral range and sensitivity of energies that the protein can utilize, increasing its subsequent photocurrent generation, a significant potential expansion of the applicability of bR in solar cell, biosensing, biocomputing, optoelectronic, and imaging technologies.

No MeSH data available.


Related in: MedlinePlus

QD lifetimes when linked to bR in PM patch form and bR monomer form compared to the QD only control. Inset displays identical QD excited state lifetime counts in Log-scale with theoretical fitting (dashed).
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fig4: QD lifetimes when linked to bR in PM patch form and bR monomer form compared to the QD only control. Inset displays identical QD excited state lifetime counts in Log-scale with theoretical fitting (dashed).

Mentions: In order to establish a FRET coupling relationship between the QD core and bR retinal that is involved in the QD emission reduction, as opposed to other absorptive or concentration effects, the excited state lifetime of the QD was measured. Utilizing a 100fs laser excitation pulse with a 25 ps resolution detection technique, the QD electrons were excited and the electron-hole recombination rates were measured. In a FRET-coupled system, a portion of the excited electron energy will transfer to the overlapping energy band in the acceptor molecule, thus reducing the amount of QD photons released over time and ultimately reducing the QD excited state lifetime. With this technique, the energy transfer relationship can be isolated from other quenching phenomenon and concentration effects. The fluorescence lifetimes were measured at the QD emission maximum of 565 nm and monitored the electron energy transfer to bR, in both monomeric and PM fragment form, when directly linked via a zero-length EDC linker. The wavelength of the excitation laser was set to 340 nm to minimize activation of the bR photoresponse. Figure 4 shows the excited state decay spectra of QD, QD-PM, and QD-bR monomer systems.


Förster Resonance Energy Transfer between Core/Shell Quantum Dots and Bacteriorhodopsin.

Griep MH, Winder EM, Lueking DR, Garrett GA, Karna SP, Friedrich CR - Mol Biol Int (2012)

QD lifetimes when linked to bR in PM patch form and bR monomer form compared to the QD only control. Inset displays identical QD excited state lifetime counts in Log-scale with theoretical fitting (dashed).
© Copyright Policy - open-access
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3376779&req=5

fig4: QD lifetimes when linked to bR in PM patch form and bR monomer form compared to the QD only control. Inset displays identical QD excited state lifetime counts in Log-scale with theoretical fitting (dashed).
Mentions: In order to establish a FRET coupling relationship between the QD core and bR retinal that is involved in the QD emission reduction, as opposed to other absorptive or concentration effects, the excited state lifetime of the QD was measured. Utilizing a 100fs laser excitation pulse with a 25 ps resolution detection technique, the QD electrons were excited and the electron-hole recombination rates were measured. In a FRET-coupled system, a portion of the excited electron energy will transfer to the overlapping energy band in the acceptor molecule, thus reducing the amount of QD photons released over time and ultimately reducing the QD excited state lifetime. With this technique, the energy transfer relationship can be isolated from other quenching phenomenon and concentration effects. The fluorescence lifetimes were measured at the QD emission maximum of 565 nm and monitored the electron energy transfer to bR, in both monomeric and PM fragment form, when directly linked via a zero-length EDC linker. The wavelength of the excitation laser was set to 340 nm to minimize activation of the bR photoresponse. Figure 4 shows the excited state decay spectra of QD, QD-PM, and QD-bR monomer systems.

Bottom Line: An energy transfer relationship between core-shell CdSe/ZnS quantum dots (QDs) and the optical protein bacteriorhodopsin (bR) is shown, demonstrating a distance-dependent energy transfer with 88.2% and 51.1% of the QD energy being transferred to the bR monomer at separation distances of 3.5 nm and 8.5 nm, respectively.Fluorescence lifetime measurements isolate nonradiative energy transfer, other than optical absorptive mechanisms, with the effective QD excited state lifetime reducing from 18.0 ns to 13.3 ns with bR integration, demonstrating the Förster resonance energy transfer contributes to 26.1% of the transferred QD energy at the 3.5 nm separation distance.The established direct energy transfer mechanism holds the potential to enhance the bR spectral range and sensitivity of energies that the protein can utilize, increasing its subsequent photocurrent generation, a significant potential expansion of the applicability of bR in solar cell, biosensing, biocomputing, optoelectronic, and imaging technologies.

View Article: PubMed Central - PubMed

Affiliation: Department of Mechanical Engineering Mechanics, Michigan Technological University, 815 RL Smith, 1400 Townsend Drive, Houghton, MI 49931, USA.

ABSTRACT
An energy transfer relationship between core-shell CdSe/ZnS quantum dots (QDs) and the optical protein bacteriorhodopsin (bR) is shown, demonstrating a distance-dependent energy transfer with 88.2% and 51.1% of the QD energy being transferred to the bR monomer at separation distances of 3.5 nm and 8.5 nm, respectively. Fluorescence lifetime measurements isolate nonradiative energy transfer, other than optical absorptive mechanisms, with the effective QD excited state lifetime reducing from 18.0 ns to 13.3 ns with bR integration, demonstrating the Förster resonance energy transfer contributes to 26.1% of the transferred QD energy at the 3.5 nm separation distance. The established direct energy transfer mechanism holds the potential to enhance the bR spectral range and sensitivity of energies that the protein can utilize, increasing its subsequent photocurrent generation, a significant potential expansion of the applicability of bR in solar cell, biosensing, biocomputing, optoelectronic, and imaging technologies.

No MeSH data available.


Related in: MedlinePlus