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Ultrathin and Isotropic Metal Sulfide Wrapping on Plasmonic Metal Nanoparticles for SERS-based Detection of Trace Heavy Metal Ions.
摘要： A facile and general strategy is presented for homogenous and ultrathin metal sulfide-wrapping on plasmonic metal (PM) nanoparticles (NPs) based on a thiourea-induced isotropic shell growth. This strategy is typically implemented just via adding the thiourea into pre-formed PM colloidal solutions containing target metal ions. The validity of this strategy is demonstrated by taking the wrapped NPs with Au core and CuS shell or Au@CuS NPs as an example. They are successfully fabricated via adding the thiourea and Cu2+ solutions into pre-formed Au NP colloidal solution. The CuS shell layer is highly homogenous (<10% in relative standard deviation of shell thickness), regardless of the NPs’ shape or curvature. The shell thickness can be controlled from tens down to 0.5 nm just by the addition amounts of the shell precursors. The formation of the shell layer on the Au NPs can be attributed to the alternative deposition of Cu2+ and S2- ions on the thiourea-modified surface of Au NPs in the solution, which induces the isotropic shell growth. Further, this strategy is of good universality. Many other sulfide-wrapped PM NPs, such as Ag@CuS, Au@PtS2, Au@HgS, Ag@Ag2S NPs and Ag@CuS nanorods have been successfully obtained with homogeneous and ultrathin shells. Importantly, such ultrathin sulfide-wrapped PM NPs can be used for SERS-based detection of trace heavy metal ions with strong anti-interference via ion exchange process between the metal sulfide shell and heavy metal ions. This study provides a simple and controllable route for wrapping the homogenous and ultrathin sulfide layers on the PM NPs, and such wrapped NPs have good practical applications in the SERS-based detection of trace heavy metal ions.
关键词： Plasmonic metal nanoparticles,Trace heavy metal ions,Ultrathin sulfide wrapping,Thiourea-induced isotropic shell growth,SERS-based detection
更新于2025-11-14 17:04:02
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Luminescence Tuning of Layered Rare-Earth Hydroxides (LRHs, R = Tb, Y) Composites with 3-Hydroxy-2-naphthoic Acid and Application to the Fluorescent Detection of Al <sup>3+</sup>
摘要： Tunable luminescence (quenching or blue shift) of HNA/OS-LRH composites (HNA is 3-hydroxy-2-naphthoic acid; OS is the anionic surfactant of 1-octanesulfonic acid sodium; LRHs are layered rare-earth hydroxides, R = Tb3+, Y3+) in the solid state and delaminated state is reported, which is utilized as an effective fluorescent probe for detecting metal ions. HNA/OS species are intercalated into LRH layers to generate composites of HNAxOS1?x-LTbH (x = 0.10, 0.15, 0.20 , 0.25) and HNAyOS1?y-LYH (y = 0.05, 0.10, 0.15, 0.20, 0.25, 0.30). In the solid state, LYH composites exhibit green emissions (from 493 to 504 nm) with a large blue shift in comparison to the 542 nm emission of free HNA? anions, while in the delaminated state in formamide (FM), the composites display blue emission (480 nm) relative to the green emission (512 nm) of an HNA soltuion in FM. However, LTbH composites display coquenched luminescence in both the solid state and delaminated state. Also, HNA0.25OS0.75-1:1-LYH, HNA0.25OS0.75-1:2-LYH, and HNA0.05OS0.95-1:1-LYH (1:1 and 1:2 are HNA:NaOH molar ratios) show significantly elongated fluorescence lifetimes of 15.35, 14.37, and 12.72 ns, respectively, in comparison with free HNA-Na (6.44 ns), and their quantum yields of 23.40%, 21.97%, and 22.31%, respectively, are much larger than that of free HNA-Na (4.86%). The LTbH composite (HNA0.25OS0.75-1:1-LTbH) has also a relatively higher quantum yield of 12.46%. The HNA0.25OS0.75-1:1-LYH colloid exhibits excellent recognition selectivity for Al3+ over other metal ions (Mg2+, Co2+, Ni2+, Cu2+, Zn2+, Pb2+, Cd2+, and Hg2+) with distinct fluorescence sensitization. It shows an intense change in its fluorescence emission when it is bound to Al3+ ions, giving a lower detection limit of 6.32 × 10?6 M. This is novel research on the fluorescence chemosensing of LRH composites.
关键词： Layered rare-earth hydroxides,Fluorescent detection,Chemosensing,Luminescence tuning,Al3+ ions
更新于2025-11-14 15:28:36
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Reversible luminescence modulation and temperature sensing properties of Pr <sup>3+</sup> /Yb <sup>3+</sup> codoped K <sub/>0.5</sub> Na <sub/>0.5</sub> NbO <sub/>3</sub> ceramics
摘要： In this work, we have prepared a novel (K0.5Na0.5)0.99-xPrxYb0.01NbO3 (abbreviated as KNN:xPr3+/0.01Yb3+, x=0.0006, 0.0008, 0.001, 0.002, 0.003 and 0.004) ceramic, which possess visible UC emissions, photochromic (PC) and optical thermometric properties. Under the excitation of a 980-nm diode laser, all the samples show the featured emissions of Pr3+ ions and the UC emission intensity is greatly dependent on the Pr3+ doping content. The optimal UC luminescence intensity is obtained at x=0.001. All the prepared samples show a strong PC reaction, and a large luminescence quenching degree (ΔRt) of 74.94% is found. The optical thermometric properties of both the irradiated and unirradiated KNN:0.001Pr3+/0.01Yb3+ ceramics in the temperature range of 123-573 K have been investigated via measuring the temperature-dependent UC emission spectra of green emissions, which originate from the two 3P1 and 3P0 thermally coupled levels. It has been found that the prepared samples have both excellent PC behaviors and temperature sensing performances. These results suggest that the KNN:xPr3+/0.01Yb3+ ceramics are promising candidates for the applications in PC reaction and thermometers.
关键词： Ferroelectrics,Thermometer,Upconversion,Rare-earth ions,Photochromism
更新于2025-11-14 15:28:36
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Synthesis, crystal structure and fluorescent sensing property of metal-organic frameworks with 1,3-di(1H-imidazol-4-yl)benzene and 1,4-phenylenediacetate
摘要： In this work, two new metal–organic frameworks (MOFs) based on 1,3-di(1H-imidazol-4-yl)benzene (L) and 1,4-phenylenediacetic acid (H2pda), namely [Ni(L)(pda)(H2O)] (1) and [Cd(L)(pda)] (2), have been achieved. MOFs 1 and 2 have distinct infinite one-dimensional (1D) chain structures, which are further linked together by hydrogen bonding interactions to give the eventual three-dimensional (3D) supramolecular architectures. Photoluminescence studies revealed that the Cd(II) MOF 2 shows strong emission at 346 nm upon excitation at 308 nm at room temperature. Furthermore, 2 can efficiently detecting acetone molecules, and Fe3+ and Cr2O7 2- ions via fluorescent quenching.
关键词： Acetone,Ions,Metal-organic frameworks,Detection,Luminescence
更新于2025-11-14 15:18:02
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Suppression of Iodide Ions Migration via Sb2S3 interfacial Modification for stable Inorganic Perovskite Solar Cells
摘要： In mixed halide perovskite, the halide phase segregation is commonly observed due to halide ions migration, which causes severe stability issues in perovskite devices. Here, we directly revealed the iodide-migration process via potentiostatic treatment in CsPbIBr2 perovskite. The absence of iodide ions was reduced significantly via Sb2S3 interfacial modification. We further employed the DFT calculation to optimize the geometry positions at the perovskite interface and radial distribution functions (RDF) to analyze the atom perturbation. The simulation yielded a slight distortion of perovskite lattice at the interface of Sb2S3-CsPbIBr2 and iodide ions fluctuation was reduced due to the decrease of halide vacancies. In addition, the thermally stimulated current was calculated to evaluate the defects density in the modified perovskite device. Due to the Sb2S3 interaction with perovskite, the device became stable against humidity and maintained photoactive over 400 h. The champion efficiency of 9.31% with 26.31% improvement was obtained in modified CsPbIBr2 perovskite solar cells.
关键词： stability,The mixed halide perovskite,Sb2S3,DFT,iodide ions migration
更新于2025-11-14 15:15:56
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Tannic acid-derivatized graphitic carbon nitride quantum dots as an “on-off-on” fluorescent nanoprobe for ascorbic acid via copper(II) mediation
摘要： A microwave-assisted hydrothermal route was employed to prepare fluorescent tannic acid (TA)-derivatized graphitic carbon nitride quantum dots. The resulting dots display blue fluorescence (best measured at excitation/emission wavelengths of 350/452 nm) with a quantum yield as high as ~44%. The incorporated TA imparts a fluorescence switching behavior in that very low concentrations of Cu(II) can quench the fluorescence, while (AA) can restore it. It is presumed that AA causes Cu(II) to be transformed to Cu(I). Based on these findings, a fluorometric method was designed for AA detection. The probe allows AA to be detected with a 50 pM limit of detection and a linear analytical range that extends from 0.1 to 200 nM of AA. Real and spiked samples were successfully assayed by the probe to demonstrate its analytical applicability.
关键词： Fluorescence recovery,Metal ions,Graphitic nanosheets,Biomolecules,Polyphenolic compounds,Optical probe,Quantum dots
更新于2025-10-22 19:40:53
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Remarkable laser-driven upconverting photothermal effect of Cs3LnF6@glass nanocomposites for anti-counterfeiting
摘要： Currently, advanced security strategies have aroused widely interest in anti-counterfeiting field to ensure the authentic items difficult to be replicated. Herein, cubic Cs3LnF6 (Ln = Y, Yb, Lu, Sc) nanocrystals embedded glasses are successfully prepared via an in-situ glass crystallization strategy. Emitting centers, such as Eu3+, Er3+, Ho3+ and Tm3+, can be incorporated into the precipitated Cs3YF6, Cs3YbF6 and Cs3LuF6 crystal lattices but remain in glass matrix rather than in Cs3ScF6 crystals for large ionic radius mismatch between lanthanide activators and Sc3+ host ions. It is demonstrated that upconverting quantum yields of all the Yb/Er: Cs3LnF6@glass samples are higher than those of well-known cubic/hexagonal Yb/Er: α/β-NaYF4@glass samples. Specifically, Yb/Er: Cs3LuF6@glass exhibits a maximal quantum yield of ~0.30%, which is superior to Yb/Er: β-NaYF4 @glass (~0.19%). Impressively, Er: Cs3YbF6@glass shows a remarkable 980 nm laser-induced photothermal effect, leading to significant alteration of upconversion emissive color from red to green with increase of incident laser power. As a prototype of the concept for practical application, a series of luminescent patterns using Er: Cs3YbF6@glass upconverting inks are constructed by a screen-printing technique and show distinct laser-power-sensitive emissive colors, being feasible for high-level anti-counterfeiting. The present work exploits a new anti-counterfeiting strategy by developing highly efficient laser-induced upconverting photothermal materials.
关键词： Anticounterfeit,Nanocomposites,Upconversion,Lanthanide ions,Photothermal effect,Luminescent glasses
更新于2025-10-22 19:38:57
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Formation of a Track Template during PETP Irradiation with High-Energy Helium Ions for the Template Synthesis of Regular Microstructures
摘要： The features of obtaining track membranes (TMs) with the help of a classical cyclotron situated at Tomsk Polytechnic University are discussed. It is demonstrated that TMs can be employed as templates. The results of research into columnar nanostructures formed with the help of a TM template are presented. The creation of regular microstructures is investigated using deep X-ray lithography with synchrotron radiation and templates made of track membranes.
关键词： track membrane,argon ions,synchrotron radiation,helium ions,polyethylene terephthalate
更新于2025-09-23 15:23:52
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A Fluorescence Light-up Silver Nanocluster Beacon Modulated by Metal Ions and Its Application in Telomerase Activity Detection
摘要： DNA-templated silver nanoclusters (DNA-AgNCs) have been extensively studied in recent years. The enhancement of fluorescence emission from the DNA-AgNCs is still being explored. Herein, we report a new study on the fluorescence enhancement of DNA-AgNCs induced by metal ions. The enhancement is greatly dependent on the primary sequence and secondary structure of DNA strands. Thus, a label-free AgNCs-based molecular beacon (MB) is explored for the detection of telomerase activity. Nonfluorescent MB-AgNCs in phosphate buffer emit a dramatic red fluorescence when Mg2+ is introduced, whereas Mg2+ has a limited effect on the weak fluorescence of DNA-AgNCs when the hairpin structure of MB is opened. Telomerase primer (TP) can be elongated by telomerase, resulting in the unfolding of MB via strand displacement reaction. Based on the different brightnesses of AgNCs produced by the two DNA templates, telomerase activity is detected. MB-AgNCs sensing platform provides a simple and low-costing method to detect telomerase activity and shows a great potential in the construction of cost-effective probes for biomolecular detection.
关键词： telomerase detection,DNA,fluorescence enhancement,silver nanocluster,metal ions
更新于2025-09-23 15:23:52
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The effects of multicharged ion irradiation on a polycarbonate surface
摘要： Polycarbonate targets were irradiated with multicharged ions of argon and oxygen with kinetic energies between 375 eV and 1 keV. Scanning electron microscopy (SEM) and x-ray photoelectron spectroscopy (XPS) analysis following the irradiations showed evidence of bond-breaking at the polycarbonate surface. The extent of the ion-induced damage indicates that the ion charge state enhances the damage well beyond that observed for similar, low flux singly charged ions. A qualitative comparison with a simple description of the radius of capture for the initial transfer of electrons between the ion and surface is used to understand the multicharged ion effects.
关键词： XPS,polycarbonate,Multicharged ions
更新于2025-09-23 15:23:52