Surface plasmon enhanced energy transfer between type I CdSe/ZnS and type II CdSe/ZnTe quantum dots (original) (raw)
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Nano Letters, 2011
Fluorescence resonant energy transfer ͑FRET͒ has been investigated between donor-acceptor pairs of type I CdSe/ZnS and type II CdSe/ZnTe quantum dots ͑QDs͒. An Au nanoparticles assisted FRET enhancement was clearly demonstrated. It is found that the efficiency of the energy transfer depends on the excitation wavelength and is largest when in resonance with the Au surface plasmon mode. With the large tunability of the emission intensity in near infrared region, our finding paves an excellent route for creating highly efficient optoelectronic devices and bioimaging labels derived from type II QDs.
Surface plasmon enhanced Förster resonance energy transfer between the CdTe quantum dots
Applied Physics Letters, 2008
Förster resonance energy transfer FRET between CdTe quantum dots QDs at nanoscale proximity to gold nanoparticle Au NP layers is investigated experimentally. We have observed the enhancement in the acceptor QDs' photoluminescence lifetime intensities. The decrease in donor QDs' exciton lifetime from 5.74 to 2.06 ns, accompanied by an increase in acceptor QDs' exciton lifetime from 3.38 to 7.52 ns, provided evidence for enhanced FRET between the QDs near Au NPs. The Au NPs' surface plasmon dipole fields are assisted to overcome the weak electronic coupling between the emitting donor and absorbing acceptor transition exciton dipoles in the homogeneous medium.
Semiconductor QDs have emerged as a novel class of fluorophore with unique photoluminescence properties, in particular, CdSe/ZnS core-shell QDs have been successfully used as biocompatible fluorescence resonance energy transfer donors. Here we report FRET between CdSe/ZnS core-shell QDs (donor) and organic dye fluorescein 27 (F27) (acceptor). The results demonstrate the occurrence of efficient energy transfer in the system and the FRET efficiency is not only influenced by the spectral overlap between the QD donor emission and acceptor absorption, it might depend on QDs surface effect also. Efforts are made to correlate quantitatively spectral dependence of FRET rate with acceptor absorption spectrum, Forster distance, transfer efficiency (E) obtained employing steady-state & time-resolved technique. Figure 3. Steady state Stern-Volmer plots of F0/F vs. concentration of quencher: (A) QD1 and (B) QD2.
FRET from CdSe/ZnS Core-Shell Quantum Dots to Fluorescein 27 Dye
Semiconductor QDs have emerged as a novel class of fluorophore with unique photoluminescence properties, in particular, CdSe/ZnS core-shell QDs have been successfully used as biocompatible fluorescence resonance energy transfer donors. Here we report FRET between CdSe/ZnS core-shell QDs (donor) and organic dye fluorescein 27 (F27) (acceptor). The results demonstrate the occurrence of efficient energy transfer in the system and the FRET efficiency is not only influenced by the spectral overlap between the QD donor emission and acceptor absorption, it might depend on QDs surface effect also. Efforts are made to correlate quantitatively spectral dependence of FRET rate with acceptor absorption spectrum, Forster distance, transfer efficiency (E) obtained employing steady-state & time-resolved technique. M. A. SHIVKUMAR ET AL. 41 Figure 3. Steady state Stern-Volmer plots of F0/F vs. concentration of quencher: (A) QD1 and (B) QD2.
CdSe−ZnS Quantum Dots as Resonance Energy Transfer Donors in a Model Protein−Protein Binding Assay
Nano Letters, 2001
Specific binding of biotinilated bovine serum albumin (bBSA) and tetramethylrhodamine-labeled streptavidin (SAv−TMR) was observed by conjugating bBSA to CdSe−ZnS core−shell quantum dots (QDs) and observing enhanced TMR fluorescence caused by fluorescence resonance energy transfer (FRET) from the QD donors to the TMR acceptors. Because of the broad absorption spectrum of the QDs, efficient donor excitation could occur at a wavelength that was well resolved from the absorption spectrum of the acceptor, thereby minimizing direct acceptor excitation. Appreciable overlap of the donor emission and acceptor absorption spectra was achieved by size-tuning the QD emission spectrum into resonance with the acceptor absorption spectrum, and cross-talk between the donor and acceptor emission was minimized because of the narrow, symmetrically shaped QD emission spectrum. Evidence for an additional, nonspecific QD−TMR energy transfer mechanism that caused quenching of the QD emission without a corresponding TMR fluorescence enhancement was also observed.
Emission transformation in CdSe/ZnS quantum dots conjugated to biomolecules
Journal of Photochemistry and Photobiology B: Biology, 2017
The variation of photoluminescence (PL) spectra in CdSe/ZnS quantum dots (QDs) at the conjugation to antibodies (ABs) has been investigated and discussed in this paper. Two types of CdSe/ZnS QDs with different CdSe core sizes (5.4 and 6.4 nm) and emissions (605 and 655 nm) were studied before and after the conjugation to anti-Interleukin-10 (IL-10) and anti-Pseudo rabies virus (PRV) ABs. The PL high energy shift and asymmetric shape of PL bands have been detected in bioconjugated QDs. Note that the bioconjugation impact on spectral characteristics of CdSe/ZnS QD emission has been not studied yet in details. The surface enhanced Raman scattering (SERS) effect is revealed in bioconjugated CdSe/ZnS QDs. The SERS effect testifies that the excitation light used at the Raman study generates the electric dipoles in AB molecules. At the same time, the permanent position of LO-phonon Raman lines in Raman spectra of nonconjugated and bioconjugated QDs confirms that QD materials do not change at the bioconjugation. It is shown as well that the compressive strains do not play any role in the PL high energy shift in bioconjugated QDs. PL spectra of pure anti IL-10 ABs, anti PRV ABs, a phosphate buffer saline (PBS) and PL spectrum dependences versus excitation light intensities have been investigated as well. Finally, the PL spectrum transformation in bioconjugated QDs is attributed to varying the quantum confinement effect in CdSe/ZnS QDs and the energy band profiles in QD cores. Both these effects are stimulated by the electromagnetic field of excited AB dipoles. The obtained results can be useful for sensitivity improving the QD bio-sensors.
Proceedings of Spie the International Society For Optical Engineering, 2007
Förster resonant energy transfer (FRET) between the CdTe quantum dot (QD) acting as donors and acceptors is investigated at nanoscale proximity to gold nanoparticles (Au NPs). Photoluminescence (PL) studies of the acceptor QD emission from a mixed monolayer showed a distance dependent enhancement of the acceptor emission compared with that achieved for a donor-acceptor mixed monolayer in the absence of the Au NP layer. Time-resolved photoluminescence measurements showing a reduction in the donor lifetime, accompanied by an increase in the acceptor PL lifetime, provide further evidence for surface plasmon enhanced FRET.
Plasmonics: Metallic Nanostructures and Their Optical Properties V, 2007
Förster resonant energy transfer (FRET) between the CdTe quantum dot (QD) acting as donors and acceptors is investigated at nanoscale proximity to gold nanoparticles (Au NPs). Photoluminescence (PL) studies of the acceptor QD emission from a mixed monolayer showed a distance dependent enhancement of the acceptor emission compared with that achieved for a donor-acceptor mixed monolayer in the absence of the Au NP layer. Time-resolved photoluminescence measurements showing a reduction in the donor lifetime, accompanied by an increase in the acceptor PL lifetime, provide further evidence for surface plasmon enhanced FRET.
Nano Letters, 2005
Nanoengineered fluorescent response is reported from semiconductor core−shell (CdSe/ZnS) quantum dots in proximity to the surface plasmon polariton field of periodic Ag nanoparticle arrays. Tuning the surface plasmon polariton resonance to the quantum dot exciton emission band results in an enhancement of up to ∼50-fold in the overall fluorescence efficiency, in a design where each Ag nanoparticle is interconnected by a continuous Ag thin film. Propagating modes of surface plasmon resonances have a direct impact on the fluorescence enhancement.
Molecular Crystals and Liquid Crystals, 2005
The reversible modulation of the emission of CdSe=ZnS semiconductor nanocrystals (quantum dots) was achieved by binding photochromic diheteroarylethenes and switchable acceptors for fluorescence resonance energy transfer. A biotinylated diheteroarylethene derivative was bound to quantum dots bearing conjugated streptavidin, leading to an intensity decrease as a consequence of energy transfer to the closed form of the acceptor. Interconversion between the open and closed forms by irradiation with 365 and 546 nm light enabled deactivation and activation, respectively, of the FRET process with a corresponding modulation of quantum dot emission, observed both in solution and by sequential wide-field imaging.