- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
NIR-Fluorescent Multidye Silica Nanoparticles with Large Stokes Shifts for Versatile Biosensing Applications
摘要： We have synthesized and characterized of a series of single and multidye copolymerized nanoparticles with large to very large Stokes shifts (100 to 255 nm) for versatile applications as standalone or multiplexed probes in biological matrices. Nanoparticles were prepared via the St?ber method and covalently copolymerized with various combinations of three dyes, including one novel aminocyanine dye. Covalently encapsulated dyes exhibited no significant leakage from the nanoparticle matrix after more than 200 days of storage in ethanol. Across multiple batches of nanoparticles with varying dye content, the average yields and average radii were found to be highly reproducible. Furthermore, the batch to batch variability in the relative amounts of dye incorporated was small (relative standard deviations <2.3%). Quantum yields of dye copolymerized nanoparticles were increased 50% to 1000% relative to those of their respective dye-silane conjugates, and fluorescence intensities were enhanced by approximately three orders of magnitude. Prepared nanoparticles were surface modified with polyethylene glycol and biotin and bound to streptavidin microspheres as a proof of concept. Under single wavelength excitation, microsphere-bound nanoparticles displayed readily distinguishable fluorescence signals at three different emission wavelengths, indicating their potential applications to multicolor sensing. Furthermore, nanoparticles modified with polyethylene glycol and biotin demonstrated hematoprotective qualities and reduced nonspecific binding of serum proteins, indicating their potential suitability to in vivo imaging applications.
关键词： Fluorescent silica nanoparticles,Biocompatible nanoparticles,Large stokes shift,Near-infrared fluorescence,Multicolor assay,Resonance energy transfer
更新于2025-09-23 15:23:52
-
Observation of Site-Resolved Vibrational Energy Transfer Using a Genetically Encoded Ultrafast Heater
摘要： Allosteric information transfer in proteins has been linked to distinct vibrational energy transfer (VET) pathways in a number of theoretical studies. Experimental evidence for such pathways, however, is sparse because site-selective injection of vibrational energy into a protein, i.e. localized heating, is required for their investigation. Here, we solve this problem by the site-specific incorporation of the non-canonical amino acid β-(1-azulenyl)-L-alanine (AzAla) via genetic code expansion. Being an exception to Kasha′s rule, AzAla undergoes ultrafast internal conversion and heating after S1 excitation while upon S2 excitation it serves as a fluorescent label. We endowed PDZ3, a protein interaction domain of postsynaptic density protein 95, with this ultrafast heater at two distinct positions. Using ultrafast IR spectroscopy, we could indeed observe VET from the incorporation sites in the protein to a bound peptide ligand on a picosecond timescale. This approach based on genetically encoded AzAla paves the way for detailed studies of VET and its role for function in a wide range of proteins.
关键词： protein modification,energy transfer,non-canonical amino acid,time-resolved spectroscopy,mutagenesis
更新于2025-09-23 15:23:52
-
A turn-on fluorescent probe for vitamin C based on the use of a silicon/CoOOH nanoparticle system
摘要： The authors describe a fluorometric method for the turn-on determination of vitamin C (ascorbic acid). The blue fluorescence of silicon nanoparticles (SiNPs; with excitation/emission maxima at 350/450 nm) is found to be quenched by CoOOH nanoparticles (NPs). In the presence of vitamin C, the CoOOH NPs are decomposed by a redox reaction between the diol group of vitamin C and CoOOH NPs. As a result, fluorescence recovers. On the basis of this finding, a fluorometric method was designed for the turn-on detection of vitamin C. Under optimal conditions, the method has a low detection limit (0.47 μM) and a linear response in the 0.5 μM to 20 μM a concentration range. It was successfully applied to the determination of vitamin C in spiked red grape and orange juice, and in vitamin C tablets.
关键词： Fluorescence Bturn-on^ strategy,Cobalt oxyhydroxide nanoparticles,Fluorometry,Stern-Volmer plot,Surface energy transfer,Redox reaction,Inner filter effect,Quenching,Silicon nanoparticles
更新于2025-09-23 15:23:52
-
Simultaneous Singlet–Singlet and Triplet–Singlet F?rster Resonance Energy Transfer from a Single Donor Material
摘要： For almost 70 years, F?rster resonance energy transfer (FRET) has been investigated, implemented into nowadays experimental nanoscience techniques, and considered in a manifold of optics, photonics and optoelectronics applications. Here, we demonstrate for the first time simultaneous and efficient energy transfer from both donating singlet and triplet states of a single photoluminescent molecular species. Using a biluminescent donor that can emit with high yield from both excited states at room temperature allows to apply the FRET framework to such a bimodal system. It serves as an exclusive model system where the spatial origin of energy transfer is exactly the same for both donating spin states involved. Of paramount significance are the facts that both transfers can easily be observed by eye and that F?rster theory is successfully applied to state lifetimes spanning over eight orders of magnitude.
关键词： organic light-emitting diodes,energy transfer,biluminescence,dual state FRET
更新于2025-09-23 15:23:52
-
Highly Efficient Luminescent Liquid Crystal with Aggregation-Induced Energy Transfer
摘要： A luminescent liquid crystal molecule (TPEMes) with efficient solid-state emission is rationally constructed via the chemically conjugation of blue-emitting tetraphenylethene cores and luminescent mesogenic tolane moieties, which are both featured with aggregation-induced emission properties. As for this fluorophore, aggregation induced energy transfer from the emissive tolane mesogens to the lighting-up tetraphenylethene units endows the molecule pure blue emission in the suspension and bulk state. Combining DSC, POM and 1D XRD experiments, TPEMes is deduced to adapt thermodynamically more stable layered crystalline phase, and can be 'frozen' into a monotropic smectic mesophase due to kinetic reasons. As a result of more densely packing of TPEMes in the crystalline phase indicated by 1D XRD, the luminescence of TPEMes in crystalline phase has blue-shifted with 17 nm relative to the metastable mesophase.
关键词： tolane,tetraphenylethene,aggregation induced emission,aggregation induced energy transfer,hexagonal columnar phase,luminescent liquid crystals
更新于2025-09-23 15:23:52
-
Electrochemiluminecence nanogears aptasensor based on MIL-53(Fe)@CdS for multiplexed detection of kanamycin and neomycin
摘要： A dual gears electrochemiluminecence (ECL) aptasensing strategy for multiple selective determination of kanamycin and neocycin was designed on the basis of the combination of kannamycin and neocycin induced dual gears conversion, the loading platform of metal-organic frameworks (MOFs), surface plasmon resonance (SPR) and ECL resonance energy transfer (ERET) between CdS QDs and AuNPs (or PtNPs). In the absence of target, the dual gears were "off". Then the B1-AuNP (gear B) and aptamer 1-PtNPs acted as signal quenching elements to quench ECL intensity due to ERET process. Upon addition of kanamycin, the aptamer 1-PtNPs were removed from the gear gradually, the ECL was enhanced due to SPR process between AuNPs and CdS QDs. After the incubation of aptamer 2, the dual gears were "off" again and ECL intensity was decreased by ERET process between AuNPs and CdS QDs. In the presence of neomycin, dual gears were "on" again, the ECL signal was enhanced by SPR process between AuNPs and CdS QDs. Under optimal condition, the proposed aptasensor exhibited wide linear ranges of kanamycin (10-10- 10-6 M) and neomycin (10-9 -10-5 M), and relatively low detection limits to kanamycin (1.7×10-11 M) and neomycin (3.5×10-10 M). The developed aptasensor realized the multiple ECL detection of kanamycin and neomycin with single luminophore, and was successfully applied to the detection of kanamycin and neomycin in food samples.
关键词： electrochemiluminecence resonance energy transfer,electrochemiluminescence,antibiotic,nanogears,surface plasmon resonance
更新于2025-09-23 15:23:52
-
G-quadruplex specific dye-based ratiometric FRET aptasensor for robust and ultrafast detection of toxin
摘要： G-quadruplex specific dyes are powerful tools for probing nucleic acid structures. Among nucleic acids, aptamers are of great interest, and widely exploited to construct versatile bioassays. Herein, based on G-quadruplex selective dye, thioflavin T (ThT), for probing the intrinsic structure of aptamers, we proposed a ratiometric fluorescence resonance energy transfer (FRET) aptasensor enabling robust and ultrafast detection of toxin. The binding of target ochratoxin A (OTA) would destruct the G-quadruplex structure of aptamer. It would lead to the detachment of ThT dye from aptamer which diminished the FRET effect between ThT and terminal-labeled dye, thus allowing quantification of OTA via FRET signals. The FRET aptasensor would confer an enhancement of 76.9% of signal to background ratio compared to the ThT-based non-FRET aptasensor. Remarkably, the FRET mechanism would eliminate the signal fluctuation resulted from varied probe concentration, thus benefiting the robustness of the assay. The aptasensor could achieve a detection of limit of 0.38 ng/mL for OTA detection. And the detection of OTA could be finished within 30 s. Besides, the assay was successful in analyzing OTA in coffee and oat samples with recoveries rate of 93.93%–107.59%. Therefore, G-quadruplex specific dye-based probing and FRET method would be a compelling design strategy for aptasensor, and may facilitate their practical application in food safety and environmental screening.
关键词： Fluorescence resonance energy transfer,G-quadruplex specific dyes,Homogeneous analysis,Toxin,Thioflavin T,Aptamer
更新于2025-09-23 15:23:52
-
Near-infrared quantum cutting via energy transfer in Bi3+, Yb3+ co-doped Lu2GeO5 down-converting phosphor
摘要： In recent years, down-converting phosphors have grown rapidly and been still growing for their potential to significantly improve the photoelectric conversion efficiency of silicon-based solar cells. However, the discovery of new optical materials with optimized properties (in terms of emission intensity, chemical and thermal stability and quantum yield) would still be of the utmost importance. Herein, we report a novel down-converting phosphor Lu2GeO5: Bi3+, Yb3+. Our research results show that the energy transfer efficiency from Bi3+ to Yb3+ in Lu2GeO5 is as high as 65%. Via such an energy transfer from Bi3+ to Yb3+, an absorbed ultraviolet photon gives rise to almost two emitted infrared photons. The theoretical quantum yield of Lu2GeO5: Bi3+, Yb3+ system is calculated to reach up to 165%. The mechanism of the energy transfer from Bi3+ to Yb3+ is proved to be an electric dipole-dipole interaction. Meanwhile, Lu1.87GeO5: 0.03Bi3+, 0.10 Yb3+ phosphor exhibits an excellent resistance against thermal quenching. The present investigation provides people a new down-converting phosphor Bi3+, Yb3+ co-doped Lu2GeO5 with near-infrared quantum cutting to achieve high photoelectric conversion efficiency of silicon-based solar cells.
关键词： Lu2GeO5: Bi3+, Yb3+,Quantum cutting,Energy transfer,Down-converting phosphors
更新于2025-09-23 15:23:52
-
Investigation of ultrafast energy transfer mechanism in BODIPY–Porphyrin dyad system
摘要： Novel β-fused BODIPY-Porphyrin compounds that contain free base porphyrin (TPP2BDP) and its Ni(II) complex (NiTPP2BDP) were synthesized to investigate intramolecular energy transfer mechanisms of β-fused BODIPY-porphyrin dyads and effect of the unfilled d shell metal ion on energy transfer mechanism. Fluorescence spectra of compounds exhibited that BODIPY emission was diminished upon excitation of the BODIPY unit because of the energy transfer from BODIPY to porphyrin unit. Femtosecond pump-probe spectroscopy measurements revealed that energy transfer of investigated compounds are faster than previous studies in literature. Rapid energy transfer (about 500 fs) from BODIPY to porphyrin was observed for both compounds when BODIPY unit is excited due to direct linkage of BODIPY to porphyrin unit. Intersystem crossing mechanism was also observed for the compound that contains free base porphyrin (TPP2BDP), whereas d-d transition was observed for the compound that contains metalloporphyrin (NiTPP2BDP) due to unfilled d orbital of Ni(II) ion.
关键词： Fast energy transfer,Borondipyrromethene,Porphyrin,Ultrafast pump-probe spectroscopy
更新于2025-09-23 15:23:52
-
Spectroscopic peculiarities of excitation and emission processes as well as relaxation dynamic of excited states in doubly and triply doped Gd3Ga3Al2O12:Ln3+ (Ln3+=Eu3+, Tb3+, Ce3+) crystals
摘要： Spectroscopic properties of Gd3Ga3Al2O12 (GGAG) single crystals co-doped with various configurations of (Eu + Tb); (Eu + Ce); (Tb + Ce) and (Eu+ Tb + Ce) ions have been investigated. The effect of distinct Ln3+ co-doping variations on luminescence of garnet crystals was studied using the different excitation wavelengths. The Ln3+-Ln3+ and host-Ln3+ interplays have been considered in doubly and triply doped GGAG:Ln3+. The crystals containing cerium ions are characterized by mainly broadband emission in the 450–750 nm spectral region that is adequately modified in green and red spectral range in the samples co-doped with terbium and europium, respectively. The Eu3+ luminescence in materials under study is selectively excited employing solely f-f europium transitions. Contrary to that, emission of terbium and cerium occur as result of interaction with Gd3+ and adjacent co-dopants.
关键词： GGAG garnet crystals,Luminescence,Ln-Ln energy transfer
更新于2025-09-23 15:23:52