We used Optically Stimulated Luminescence (OSL) from X-ray-irradiated sodium chloride nanocrystals to investigate how silver nanoparticle (AgNP) films enhanced luminescence. We controlled the emitter-AgNP distance and used the OSL intensity and decay times to explore the plasmonic interactions underlying the enhanced luminescence. Both intensity and decay times depended on the emitter-AgNP distance, which suggested that a mechanism involving energy transfer from the localized surface plasmons (LSPs) to the trapped electrons took place through a distance-dependent coupling. Compared to other plasmon-enhanced mechanisms, the energy transfer observed here occurred in the opposite bias: LSP relaxation stimulated electron transfer from non-optically active traps to optically active traps, which culminated in enhanced emission. Therefore, a different mechanism of plasmonic coupling converted optically unreachable electrons into useful luminescence information.
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http://dx.doi.org/10.1038/srep36691 | DOI Listing |
ACS Cent Sci
November 2024
Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States.
Structural gating provides a molecular means to transfer electrons preferentially in one desired vectorial direction, a behavior needed for applications in artificial photosynthesis. At the interfaces utilized herein, visible-light absorption by a transition metal complex a "structural gate" by planarization of otherwise rotating phenyl rings in phenylene ethynylene (PE) bridge units. Planarization provides a conjugated pathway for electron flow toward a conductive oxide surface.
View Article and Find Full Text PDFJ Phys Chem A
December 2024
INL - International Iberian Nanotechnology Laboratory, Av. Mestre José Veiga, Braga 4715-330, Portugal.
We present the development of an advanced sensing platform using a monolayer of graphene functionalized with fluorophore-labeled DNA hairpins to detect the kinetics of single hairpins during the hybridization reaction. The near-field photonic effects of graphene induce a distance-dependent quenching effect on the attached fluorescent labels, resulting in distinct optical signals in response to axial displacements resulting from DNA hybridization. Employing a wide-field Total Internal Reflection Fluorescence (TIRF) optical setup coupled with a sensitive Electron-Multiplying Charge-Coupled Device (EM-CCD) camera, we successfully detected fluorescent signals of individual or a low number of individual DNA hairpins within a low-concentration environment DNA target (tDNA).
View Article and Find Full Text PDFJ Am Chem Soc
December 2024
State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, Xiamen 361005, China.
C-H···π interactions, a prevalent intermolecular force, play a pivotal role in chemistry, materials science, and life sciences. Despite extensive studies of their influence on intermolecular binding configurations and energetics, their impact on intermolecular coupling and charge transport remains unexplored. Here, we investigate the charge transport within supramolecular junctions connected by C-H···π and π-π interactions, respectively, and find that C-H···π interactions exhibit conductances that are 3.
View Article and Find Full Text PDFChemistry
January 2025
School of Materials Science and Engineering, China University of Petroleum (East China), Qingdao, 266580, China.
To investigate the effect of the through-bond coupling strength on the symmetry-breaking charge separation (SB-CS) dynamics and mechanism, three 9,10-bis((4-hexylphenyl)ethynyl)anthracene dimers with varying distances, viz., a single-bond linked dimer (0-dimer), a phenylene linked dimer (1-dimer) and a para-biphenylene linked dimer (2-dimer), were synthesized and studied systematically using steady-state and transient spectroscopy. Steady-state absorption spectra revealed that the electronic coupling strength decreased gradually with the increase of the inter-chromophore distance, and the transition of S→S includes the dark charge transfer (CT) excitation.
View Article and Find Full Text PDFYing Yong Sheng Tai Xue Bao
June 2024
2 College of Economics and Management, Hebei Agricultural University, Baoding 071000, Hebei, China.
Quantifying the impact of competition on individual tree biomass and its distribution pattern can provide a basis for improving the prediction accuracy of forest biomass models. To accurately quantify the effects of competition factors on individual biomass and its distribution, we constructed three different individual biomass models by using nonlinear coupling equations based on the biomass survey data of 50 from 18 plots of Pangu Forest Farm in Daxing'an Mountains. M-1 was a traditional singly additive biomass model.
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