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Highly -sensitive near infrared luminescent nanothermometers based on binary mixture
摘要： We propose a simple strategy to obtain a luminescence intensity ratio nanothermometer operating in the near infrared range (1000 – 1700 nm) by use of binary mixtures of lanthanide doped Y2O3 selected as 1%Ho - Y2O3 + 1%Er - Y2O3 and 1%Ho - Y2O3 + 1%Nd - Y2O3. All nanoparticles were synthetized by citrate complexation method and thermally annealed at 800 °C. The temperature evolution of the emission properties was monitored in the range of 297 – 472 K and analyzed in terms of emission shape, intensity, dynamics, excitation wavelength, acquisition mode and weight ratio of the binary mixture. A maximum relative sensitivity of 1%K-1 at 297 K was recorded for the 3:1 weight ratio Ho – Y2O3 + Er – Y2O3 binary mixture upon excitation at 536.8 nm. For the more appropriate excitation wavelength for bioimaging applications at 649.7 nm, a relative sensitivity of 0.55 - 0.6 % K-1 was recorded in the relevant physiological temperature range (300 -320 K) for the 3:1 weight ratio Ho – Y2O3 + Er – Y2O3 binary mixture. To the best of our knowledge, our study also represents a first report on the near -infrared luminescence (around 1200 nm) lifetime thermometry for a Ho doped nanoparticle. Comparison with the literature demonstrates that our system represents a promising near-infrared thermometer, with a non-sophisticated and reproducible configuration that is open to multiple optimization routes.
关键词： Lifetime thermometry,Binary mixture,lanthanide doped Y2O3,Near infrared luminescence,Self-referenced nanothermometry
更新于2025-09-23 15:22:29
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Quantum Dot-Based Sensitization System for Boosted Photon Absorption and Enhanced Second Near-Infrared Luminescence of Lanthanide-Doped Nanoparticle
摘要： Efficient energy transfer is a promising strategy in overcoming the inherent limits of narrow band and weak absorption of lanthanide ions due to the nature of 4f-4f transitions. Herein, we introduce a nanoparticle-sensitized nanoparticle system where a near-infrared-emitting quantum dot (QD) is used as a sensitizer with broadband photon absorption for lanthanide-doped nanoparticle (LNP) to generate second near-infrared (NIR-II) emission. The NIR-II luminescence of Er3+-doped LNP by Ag2S QD sensitization displays an enhancement of ~17-fold in intensity and ~10-fold in brightness over bare LNP because of increased absorptivity and overall broadening of the absorption spectrum of LNP. Furthermore, QD-sensitized LNP system exhibits excellent photostability, and is able to improve the signal to noise ratio of tumor NIR-II imaging via in situ crosslinking of QD and LNP. The QD-sensitized LNP system for luminescence enhancement opens a potential avenue for efficient energy transfer in complex nanoparticle-nanoparticle systems.
关键词： Lanthanide-Doped Nanoparticle,Photon Absorption,Second Near-Infrared Luminescence,Quantum Dot,Sensitization System
更新于2025-09-23 15:21:01
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Modulation of the properties of dinuclear lanthanide complexes through utilizing different ?2-diketonate co-ligands: near-infrared luminescence and magnetization dynamics
摘要： A family of new dinuclear lanthanide complexes as the simplest entities showing intramolecular magnetic interactions, [Ln2(dbm)2(L)2(CH3OH)2] (Ln = Tb (1), Dy (2), Ho (3), Er (4), Yb (5), Lu (6)), [Ln2(acac)2(L)2(EtOH)2] (Ln = Dy (7), Er (8)), [Dy2(TTA)2(L)2(CH3OH)2]·2CH2Cl2 (9) and [Dy2(tfa)2(L)2(CH3OH)2] (10) (H2L = N’-(2-hydroxy-5-methylphenyl)-pyrazine-2-carbohydrazide, Hdbm = 1,3-diphenyl-1,3-propanedione, Hacac = acetylacetone, HTTA = 2-thenoyltrifluoroacetone, Htfa = trifluoroacetylacetone), were constructed successfully by the reaction of a Schiff base ligand H2L and four different β-diketonate salts. As for complexes 4, 5 and 8, all exhibit the characteristic emission peaks of the corresponding Er3+, Yb3+ and Er3+ ions, respectively. Meanwhile, the excitation wavelength (510 nm) of 5 is located in the visible region, confirming its significant potential application value. Magnetic studies indicate that complexes 9 and 10 exhibit characteristic slow relaxation of magnetization with the energy barriers (Ueff) of 102 K for 9 and 140 K for 10 under a zero dc field. Under the optimized dc fields, slow magnetic relaxations are present in 2 and 7, and the Ueff values of 9 and 10 have been improved. This proves that the β-diketonate co-ligands deserve an important role in regulating Dy-SMMs influenced by the diverse perturbations of the axial crystal field originating from minor changes in the coordination environment.
关键词： single-molecule magnets,dinuclear lanthanide complexes,β-diketonate co-ligands,near-infrared luminescence,magnetization dynamics
更新于2025-09-23 15:19:57
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Luminescence of Cr3+/Yb3+ co-doped oxyfluoride silicate glasses for crystalline silicon solar cell down-conversion devices
摘要： Oxy?uoride silicate glasses co-doped with Cr3+ and Yb3+ ions were fabricated in this work. High △T (178–214 °C) value demonstrated that the thermal stability of the prepared glasses were better than tellurite and germanate glasses. X-ray di?raction (XRD) curves proved the amorphous nature of the glasses, the energy dispersive spectroscopy (EDS) analysis and Fourier Transform infrared spectroscopy (FT-IR) curves explored the network structure of glasses. The photoluminescence excitation (PLE) and photoluminescence emission (PL) spectra show that the glasses absorption peaks located at 430 nm (Cr3+:4A2g - 4T1g (P)) and 627 nm (Cr3+:4A2g - 4T2g), while the emission peak close to 1010 nm (Yb3+:2F5/2 -2F7/2), which meets the condition of energy down-conversion. Besides, the energy transfer e?ciency (ηCET = 33.5%) and the quantum cutting e?ciency (ηQE = 133.5%) were calculated from the measured decay curves. These values were higher than Cr3+/Yb3+ co-doped ?uorosilicate glass with incorporating of CaF2 (21.5% and 123.5%) and Tb3+/Yb3+ oxy?uoride glass (13.5% and 113.5%), indicating the prepared samples are conducive to the energy transfer from Cr3+ to Yb3+ ions. The experimental results reveal that the oxy?uoride silicate glasses have potential application prospects in crystalline silicon (c-Si) solar cells.
关键词： Oxy?uoride silicate glasses,Melt-quenching method,Down-conversion and near-infrared luminescence emission,Crystalline silicon (c-Si) solar cells
更新于2025-09-19 17:13:59
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Bi-Activated Glasses and their Potential Covering Spectral Region as Active Media for Tunable near Infrared Lasers
摘要： To obtain the near infrared luminescence Bi-activated phosphate-aluminum-natrium glasses were synthesized and treated under reduction conditions. The reduction conditions were achieved by different methods: treatment in graphite atmosphere, hydrogen atmosphere, and X-ray irradiation. The spectral-luminescent properties of glass samples were measured and analyzed. Bi-activated phosphate-aluminum-natrium glasses after reduction treatment have shown wide near infrared luminescence with two peaks at the telecommunication windows region. The nature of the luminescent centers in Bi-activated phosphate-aluminum-natrium glasses are discussed. The spectral-luminescent properties of synthesized glasses were studied at the context of Bi-activated glass as the active media for tunable near infrared lasers operating in 1050-1500 nm region. The demonstrated properties of Bi-activated phosphate-aluminum-natrium glass are promising to fill the gap in near infrared lasers operating range.
关键词： Tunable infrared lasers,near infrared luminescence,Bi-doped glasses,spectral-luminescent properties of bismuth in glass matrix
更新于2025-09-16 10:30:52
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Synthesis of Silver Sulfide Quantum Dots Via the Liquid–Liquid Interface Reaction in a Rotating Packed Bed Reactor
摘要： We developed the high-gravity coupled liquid–liquid interface reaction technique on the basis of the rotating packed bed (RPB) reactor for the continuous and ultrafast synthesis of silver sulfide (Ag2S) quantum dots (QDs) with near-infrared (NIR) luminescence. The formation of Ag2S QDs occurs at the interface of microdroplets, and the average size of Ag2S QDs was 4.5 nm with a narrow size distribution. Ag2S QDs can disperse well in various organic solvents and exhibit NIR luminescence with a peak wavelength at 1270 nm under 980-nm laser excitation. The mechanism of the process intensification was revealed by both the computational fluid dynamics simulation and fluorescence imaging, and the mechanism is attributed to the small and uniform droplet formation in the RPB reactor. This study provides a novel approach for the continuous and ultrafast synthesis of NIR Ag2S QDs for potential scale-up.
关键词： Liquid–liquid interface reaction,Rotating packed bed,Ag2S quantum dots,Near-infrared luminescence,Process intensification
更新于2025-09-12 10:27:22
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Temperature Sensing of Deep Abdominal Region in Mice by Using Over-1000 nm Near-Infrared Luminescence of Rare-Earth-Doped NaYF4 Nanothermometer
摘要： Luminescence nanothermometry has attracted much attention as a non-contact thermal sensing technique. However, it is not widely explored for in vivo applications owing to the low transparency of tissues for the light to be used. In this study, we performed biological temperature sensing in deep tissues using β-NaYF4 nanoparticles co-doped with Yb3+, Ho3+, and Er3+ (NaYF4: Yb3+, Ho3+, Er3+ NPs), which displayed two emission peaks at 1150 nm (Ho3+) and 1550 nm (Er3+) in the >1000 nm near-infrared wavelength region, where the scattering and absorption of light by biological tissues are at the minimum. The change in the luminescence intensity ratio of the emission peaks of Ho3+ and Er3+ (IHo/IEr) in the NaYF4: Yb3+, Ho3+, Er3+ nanothermometer differs corresponding to the thickness of the tissue. Therefore, the relationship between IHo/IEr ratio and temperature needs to be calibrated by the depth of the nanothermometer. The temperature-dependent change in the IHo/IEr was evident at the peritoneal cavity level, which is deeper than the subcutaneous tissue level. The designed experimental system for temperature imaging will open the window to novel luminescent nanothermometers for in vivo deep tissue temperature sensing.
关键词： near-infrared,Luminescence nanothermometry,biological window,NaYF4 nanoparticles,deep tissue temperature sensing
更新于2025-09-10 09:29:36
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Upconversion luminescence modification induced near infrared luminescence enhancement of Bi2Ti2O7:Yb3+, Er3+ inverse opals
摘要： To date, there are comprehensive researches on rare-earth doped photonic band gap (PBG) materials. The PBG materials can effectively modify the up-conversion luminescence (UCL) of rare earth ions. However, few people pay attention to the influence of modification of the UCL of rare earth ions on their near infrared (NIR) luminescence. In this article, the Bi2Ti2O7: Yb3+, Er3+ inverse opal PBG materials were prepared, and the influence of modification of the UCL of Er3+ on their NIR luminescence was investigated systematically by changing the PBG position. The green and red UCL were suppressed when the PBG was overlapped the UCL of Er3+. The UCL modification induced NIR luminescence enhancement was observed in the Bi2Ti2O7: Yb3+, Er3+ inverse opal, which was attributed to the energy redistribution caused by the PBG effect. The suppression of UCL results in that the electrons located at the UCL levels relax to the NIR luminescence level of 4I13/2, causing the NIR luminescence enhancement. Our research can provide a promising method for the enhancement of the NIR luminescence.
关键词： Enhancement,Inverse opal,up-conversion luminescence,Near infrared luminescence
更新于2025-09-04 15:30:14
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Wide-Range UV-to-Visible Excitation of Near-Infrared Emission and Slow Magnetic Relaxation in Ln <sup>III</sup> (4,4′-Azopyridine-1,1′-dioxide)[Co <sup>III</sup> (CN) <sub/>6</sub> ] <sup>3–</sup> Layered Frameworks
摘要： Trivalent lanthanide ions combined with two linkers, organic 4,4′-azopyridine-1,1′-dioxide (apdo), and inorganic hexacyanidocobaltate(III), gave a series of magnetoluminescent coordination polymers, [{LnIII(apdo)(H2O)4}{CoIII(CN)6}]·2H2O (Ln = Nd, 1; Tb, 2; Dy, 3; Er, 4; Tm, 5; Yb, 6). They are hybrid organic?inorganic layered frameworks composed of cyanido-bridged {Ln2(μ-NC)4Co2} squares linked by Ln?apdo?Ln bridges into a coordination network of a mixed 4- and 8-metal ring topology. Lanthanide(III) complexes, [LnIII(μ-apdo)2(H2O)4(μ-NC)2]+, of a distorted dodecahedral geometry are isolated by diamagnetic [CoIII(CN)6]3? and apdo linkers. As a result, 1?6 reveal field-induced slow relaxation of magnetization, with typical temperature-dependent relaxation of a single-ion origin for NdIII-containing 1, DyIII-containing 3, and YbIII-containing 6. The related alternate-current magnetic data were precisely analyzed, indicating the multiple magnetic relaxation pathways, including a direct process, strong quantum tunneling of magnetization, non-negligible Raman processes, and crucial two-phonon Orbach thermal relaxation. The thermal energy barriers of the Orbach process, ΔE/kB, are 15.1(9) K with τ0 = 9.8(9) × 10?6 s at Hdc = 4500 Oe, 16.1(8) K with τ0 = 9.0(9) × 10?5 s at Hdc = 1500 Oe, and 17.3(6) K with τ0 = 3.2(7) × 10?6 s at Hdc = 700 Oe, for 1, 3, and 6, respectively, proving the single-molecule magnet (SMM) behavior. Because of the presence of [Co(CN)6]3?, 1?6 show strong UV absorption, while the chromophoric apdo leads to the strong absorption in the visible range. As a result, the visible 4f/3d metal-centered emission is quenched, but the near-infrared luminescence from NdIII and YbIII is observed in 1 and 6, respectively. It is realized by Co-to-Ln metal-to-metal, and apdo-to-Ln ligand-to-metal energy transfers; thus, broad UV-to-visible excitation can be explored. Compounds 1?6 form a novel family of functional bimetallic assemblies, incorporating NIR-emissive SMMs as presented for NdCo (1) and YbCo (6) derivatives.
关键词： single-molecule magnets,near-infrared luminescence,coordination polymers,magnetoluminescent,lanthanide
更新于2025-09-04 15:30:14