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Energy Transfer between Tm-Doped Upconverting Nanoparticles and a Small Organic Dye with Large Stokes Shift
摘要： Lanthanide-doped upconverting nanoparticles (UCNP) are being extensively studied for bioapplications due to their unique photoluminescence properties and low toxicity. Interest in RET applications involving UCNP is also increasing, but due to factors such as large sizes, ion emission distributions within the particles, and complicated energy transfer processes within the UCNP, there are still many questions to be answered. In this study, four types of core and core-shell NaYF4-based UCNP co-doped with Yb3+ and Tm3+ as sensitizer and activator, respectively, were investigated as donors for the Methyl 5-(8-decanoylbenzo[1,2-d:4,5-d']bis([1,3]dioxole)-4-yl)-5-oxopentanoate (DBD-6) dye. The possibility of resonance energy transfer (RET) between UCNP and the DBD-6 attached to their surface was demonstrated based on the comparison of luminescence intensities, band ratios, and decay kinetics. The architecture of UCNP influenced both the luminescence properties and the energy transfer to the dye: UCNP with an inert shell were the brightest, but their RET efficiency was the lowest (17%). Nanoparticles with Tm3+ only in the shell have revealed the highest RET efficiencies (up to 51%) despite the compromised luminescence due to surface quenching.
关键词： time-resolved luminescence,core shell UCNP,DBD dye,resonance energy transfer
更新于2025-09-23 15:22:29
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A far-red FRET fluorescent probe for ratiometric detection of l-cysteine based on carbon dots and N-acetyl-l-cysteine-capped gold nanoparticles
摘要： A novel far-red fluorescence resonance energy transfer (FRET) fluorescenct probe for ratiometric detection of L-cysteine (L-Cys) has been designed. The system was established a FRET assembly by positively charged carbon dots (CDs) and negatively charged N-acetyl-L-cysteine capped gold nanoparticles (NAC-AuNPs). The fluorescence of CDs at 539 nm could be effectively quenched in the presence of NAC-AuNPs owing to FRET process, while the emission of NAC-AuNPs at 630 nm was appeared. Subsequently, the interactions between L-Cys and NAC-AuNPs resulted in the decreased emission intensity of NAC-AuNPs, but the emission intensity of CDs kept almost constant due to the continuous FRET efficiency. The ratio of emission intensities at 539 and 630 nm (I539/I630) exhibited a linear correlation to the L-Cys concentration in the range of 1.0-110 μM with the detection limit of 0.16 μM. Moreover, this far-red ratiometric sensor also revealed excellent selectivity toward L-Cys over other amino acids, which showed very high potential in the practical application for diagnosing of cysteine-related disease.
关键词： Fluorescence resonance energy transfer,gold nanoparticles,L-cysteine,Carbon dots
更新于2025-09-23 15:22:29
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Dynamic Emission Tuning of X-ray Radioluminescent Crystalline Colloidal Arrays: Coupling the Optical Stop Band with Sequential F?rster Resonance Energy Transfers
摘要： X-ray radiation exhibits diminished scattering and a greater penetration depth in tissue relative to the visible spectrum and has spawned new medical imaging techniques that exploit X-ray luminescence of nanoparticles. The majority of the nanoparticles finding applications in this field incorporate metals with high atomic numbers and pose potential toxicity effects. Here, a general strategy for the preparation of a fully organic X-ray radioluminescent colloidal platform that can be tailored to emit anywhere in the visible spectrum through a judicious choice in donor/acceptor pairing and multiple sequential F?rster resonance energy transfers (FRETs) is presented. This is demonstrated with three different types of ≈100 nm particles that are doped with anthracene as the scintillating molecule to “pump” subsequent FRET dye pairs that result in emissions from ≈400 nm out past 700 nm. The particles can be self-assembled in crystalline colloidal arrays, and the radioluminescence of the particles can be dynamically tuned by coupling the observed rejection wavelength with the dyes’ emission.
关键词： anthracene,F?rster resonance energy transfer,photonic crystals,X-ray radioluminescence,colloidal crystals
更新于2025-09-23 15:21:21
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The Unified Theory of Resonance Energy Transfer According to Molecular Quantum Electrodynamics
摘要： An overview is given of the molecular quantum electrodynamical (QED) theory of resonance energy transfer (RET). In this quantized radiation field description, RET arises from the exchange of a single virtual photon between excited donor and unexcited acceptor species. Diagrammatic time-dependent perturbation theory is employed to calculate the transfer matrix element, from which the migration rate is obtained via the Fermi golden rule. Rate formulae for oriented and isotropic systems hold for all pair separation distances, R, beyond wave function overlap. The two well-known mechanisms associated with migration of energy, namely the R?6 radiationless transfer rate due to F?rster and the R?2 radiative exchange, correspond to near- and far-zone asymptotes of the general result. Discriminatory pair transfer rates are also presented. The influence of an environment is accounted for by invoking the polariton, which mediates exchange and by introducing a complex refractive index to describe local field and screening effects. This macroscopic treatment is compared and contrasted with a microscopic analysis in which the role of a neutral, polarizable and passive third-particle in mediating transfer of energy is considered. Three possible coupling mechanisms arise, each requiring summation over 24 time-ordered diagrams at fourth-order of perturbation theory with the total rate being a sum of two- and various three-body terms.
关键词： molecular quantum electrodynamics,virtual photon exchange,resonance energy transfer,discriminatory transfer,F?rster transfer,medium effects,polariton mediated exchange,radiative exchange
更新于2025-09-23 15:21:01
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Unified theory of plasmon-induced resonance energy transfer and hot electron injection processes for enhanced photocurrent efficiency
摘要： Plasmons in metal nanoparticles (MNPs) promise to enhance solar energy conversion in semiconductors. Two essential mechanisms of enhancement in the near-field regime are hot electron injection (HEI) and plasmon-induced resonance energy transfer (PIRET). Individual studies of both mechanisms indicate that the PIRET efficiency is limited by the short lifetime of the plasmon, whereas the hot electrons result from the plasmon decay. The development of a unified theory of the coupled HEI and PIRET processes is fundamentally interesting and necessary for making reliable predictions but is complicated by the multiple interactions between various components that participate in the enhancement process. In this paper, we use the model-Hamiltonian approach to develop a combined theoretical framework including both PIRET and HEI. The coupled dynamics as well as the time evolution of hot electron energy distribution are studied. The theory further predicts an interference-induced asymmetry in the spectral dependence of PIRET, which can be used to distinguish it from HEI. As the relative contributions of PIRET and HEI strongly depend on the size of the MNPs, this presents itself as a simple route to control the strength of their contributions. The results presented here can further guide future applications of plasmonic solar energy harvesting.
关键词： plasmon,metal nanoparticles,hot electron injection,solar energy conversion,plasmon-induced resonance energy transfer
更新于2025-09-23 15:21:01
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Role of CdSe and CdSe@ZnS quantum dots interlayers conjugated in inverted polymer solar cells
摘要： We demonstrate the use of CdSe quantum dots (QDs) as an interlayer for improving photovoltaic performance in the inverted polymer solar cells (iPSCs). The conjugation of CdSe and CdSe@ZnS core@shell QDs between polyethylenimine ethoxylated (PEIE) polymer and PTB7:PC71BM blended layer played an important role in increasing the short circuit current density by F€orster resonance energy transfer (FRET) and efficient charge transport. The drastic mutual photoluminescence quenching suggests that the photon energy absorbed by PTB7:PC71BM are effectively transferred to the QDs. The PTB7:PC71BM based iPSCs with the CdSe QDs interlayer exhibits higher power conversion efficiency of 8.13%, which is 13.4% higher than that of the control device. The iPSCs with CdSe@ZnS QDs interlayer showed relatively lower PCE of 7.31%, which could be due to an increase in carrier recombination inside QDs by relatively high energy level of ZnS shell. As a consequence, the enhanced photovoltaic performance of iPSCs with CdSe QDs interlayer can be attributed to an effective charge transport and an increase in the overall photocurrent by FRET.
关键词： Carrier transport,Resonance energy transfer,Quantum dots,Inverted polymer solar cells,CdSe,Energy level alignment
更新于2025-09-23 15:21:01
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Excitation Transfer in Hybrid Nanostructures of Colloidal Ag2S/TGA Quantum Dots and Indocyanine Green J-Aggregates
摘要： The regularities of the electron excitations exchange in hybrid associates of colloidal Ag2S quantum dots, passivated with thioglycolic acid (Ag2S/TGA QDs) with an average size of 2.2 and 3.7 nm with Indocyanine Green J-aggregates (ICG) were studied in this work by methods of absorption and luminescence spectroscopy. It was shown that IR luminescence sensitization of Ag2S/TGA QDs with an average size of 3.7 nm in the region of 1040 nm is possible due to non-radiative resonance energy transfer from Ag2S/TGA QDs with an average size of 2.2 nm and luminescence peak at 900 nm using ICG J-aggregate as an exciton bridge. The sensitization efficiency is 0.33. This technique provides a transition from the first therapeutic window (NIR-I, 700-950 nm) to the second (NIR-II, 1000-1700 nm). It can allow high to increase the imaging in vivo resolution.
关键词： Non-radiative resonance energy transfer (FRET),Indocyanine green,Hybrid associate,Luminescence properties,Silver sulfide quantum dots,J-aggregates
更新于2025-09-23 15:21:01
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Paper-Based Constant Potential Electrochemiluminescence Sensing Platform with Black Phosphorus as a Luminophore Enabled by a Perovskite Solar Cell
摘要： Exploring e?cient luminophores in the electrochemiluminescence (ECL) system is highly desired to pursue a sensitive ECL sensing platform. Herein, the black phosphorus nanosheets (BP NSs) with excellent ECL properties are investigated and serve as the luminophore with the coreactant of peroxydisulfate (S2O8 2?) solution. Moreover, owing to the overlapping of emission and absorbance spectra, e?ective resonance energy transfer (RET) is realized between the BP NSs and the introduced Au nanoparticles. In order to achieve the portable and miniaturized developing trends for the paper-based ECL sensing platform, a paper-based perovskite solar cell (PSC) device is designed to act as the power source to replace the commonly utilized expensive and cumbersome electrochemical workstation. Bene?ting from that, a PSC driven paper-based constant potential ECL-RET sensing platform is constructed, thereby realizing sensitive microRNAs (miRNAs) detection. What’s more, to attain the preferable analytical performance, the duplex-speci?c nuclease (DSN) is also introduced to assist the target recycling signal ampli?cation strategy. Based on this, highly sensitive detection of miRNA-107 with a range from 0.1 pM to 15 nM is achieved by this designed sensing platform. Most importantly, this work not only pioneers a precedent for developing a high-sensitivity PSC triggered ECL sensing platform but also explores the application prospect of BP nanomaterial in the ?eld of bioanalysis.
关键词： microRNAs detection,resonance energy transfer,perovskite solar cell,black phosphorus nanosheets,electrochemiluminescence
更新于2025-09-23 15:21:01
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A new nano biosensor for maitotoxin with high sensitivity and selectivity based fluorescence resonance energy transfer between carbon quantum dots and gold nanoparticles
摘要： Maitotoxin (MTX) is a potent marine toxin with critical LD50, which usually causes poisoning because of eating the contaminated marine crustaceans. This poison is a severe threat to neuronal systems and also disables the heart by increasing the calcium ions flow in the cardiovascular. Therefore, the quantitative determination of MTX by using a fast and cost-effective way is essential. Application of carbon dots in the structure of various sensors for the measurement of biological compounds has been developed due to its easy, rapid and inexpensive synthesis. In this study, carbon quantum dots (CQDs) and gold nanoparticles (AuNPs) were synthesized for the determination of MTX with high sensitivity and selectivity. The structure of CQDs and AuNPs were characterized using SEM (Scanning electron microscopy), TEM (Transmission electron microscopy), EDS (Energy-dispersive X-ray spectroscopy) and FT-IR (Fourier-transform infrared spectroscopy) techniques. The Basis of the sensing method is fluorescence resonance energy transfer (FRET) which occurs between energy donor (CQDs) and energy acceptor (AuNPs). Under optimal conditions (excitation wavelength 430 nm and emission wavelength 523 nm), the linear range and detection limit were obtained 1-600 pmol L-1 and 0.3 pmol L-1, respectively. The strong point of this nanosensor is its very fast quenching process. The interference effect of other poisons and some ions on the MTX determination were investigated using CQDs at the constant concentration of MTX 50 pmol L-1 and various concentrations of other species. The results show excellent selectivity for the measurement of MTX in the presence of other similar species.
关键词： Gold nanoparticles,Fluorescence Resonance Energy Transfer,Maitotoxin,Carbon Quantum Dots
更新于2025-09-23 15:21:01
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An ultrasensitive homogeneous aptasensor for carcinoembryonic antigen based on upconversion fluorescence resonance energy transfer
摘要： Carcinoembryonic antigen (CEA) has been recognized as one of the most important tumor markers. Herein, we reported an ultrasensitive homogeneous aptasensor based on fluorescence resonance energy transfer (FRET) between upconversion nanoparticles (UCNPs) and graphene oxide (GO) for CEA detection. The CEA aptamer modified UCNPs can bind to the surface of GO through π-π stacking interaction, resulting in fluorescence quenching due to the energy transfer from UCNPs to GO. After the introduction of CEA, the CEA aptamer preferentially combined with CEA to form three-dimensional structure which made UCNPs-aptamer dissociate from the GO, blocking the energy transfer process. The fluorescence of UCNPs was accordingly restored in a CEA concentration-dependent manner both aqueous solution and human serum samples. The aptasensor could monitor CEA level directly in human serum and the results were strongly correlated with commercial chemiluminescence kits. The excellent detection performance suggested promising prospect of the aptasensor in practical application.
关键词： Upconversion Nanoparticles,Graphene Oxide,Fluorescence Resonance Energy Transfer,CEA,Aptasensor
更新于2025-09-23 15:21:01