Optical thermometers usually make use of the fluorescence intensity ratio of two thermally coupled energy levels, with the relative sensitivity constrained by the limited energy gap. Here we develop a strategy by using the upconversion (UC) emissions originating from two multiplets with opposite temperature dependences to achieve higher relative temperature sensitivity. We show that the intensity ratio of the two UC emissions, ³F(2,3) and ¹G₄, of Tm³⁺ in β-NaYF₄:20%Yb³⁺, 0.5%Tm³⁺/NaYF₄:1%Pr³⁺ core-shell nanoparticles under 980 nm laser excitation exhibits high relative temperature sensitivity between 350 and 510 K, with a maximum of 1.53% K⁻¹ at 417 K. This demonstrates the validity of the strategy, and that the studied material has the potential for high-performance optical thermometry.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1364/OL.39.006687 | DOI Listing |
Small
December 2024
State Key Laboratory of Heavy Oil Processing, College of Chemistry and Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580, China.
Chiral plasmonic nanomaterials have attracted significant awareness due to their applications in chiral catalysis, biosensing, photonics, and separation. Constructing plasmonic core-shell nanomaterials with geometric chirality and desirable optical chirality is a crucial yet challenging task for extending the range of chiral plasmonic nanomaterials. Here, a two-step method is reported for the synthesis of Gold (Au) branches wrapped silver (Ag) nanocubes (L/DBAg@Au) with strong and tunable circular dichroism (CD) signals under the regulation of L/D-cysteine (L/D-Cys).
View Article and Find Full Text PDFSmall
December 2024
Institute of Light and Matter, University Claude Bernard Lyon 1, CNRS, UMR5306, Villeurbanne, F-69622, France.
Bimetallic nanoparticles are used in numerous applications in catalysis, plasmonics or fuel cell technology. The addition of the second metal to the nanoparticles allows enhancing and fine-tuning their properties by choosing their composition, size, shape and environment. However, the crucial additional parameter of chemical structure within the particle is difficult to predict and access experimentally, even though segregated core-shell structures and random alloys can have drastically different physicochemical properties.
View Article and Find Full Text PDFAnal Chem
December 2024
College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, People's Republic of China.
Nowadays, optical tweezers play a vital role not only in optical manipulation but also in bioassay. As principal optical trapping objects, microbeads can combine optical tweezers with suspension array technology, with amply focused laser beams and adequately concentrated tags contributing to highly sensitive detection. In view of the inefficiency of conventional single-trap optical tweezers, multitrap systems are developed.
View Article and Find Full Text PDFWater Res
December 2024
State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, PR China. Electronic address:
Nanofiltration (NF) is crucial for advancing water purification and wastewater reuse technologies. Incorporating biocidal nanoparticles (NPs) such as AgNPs and CuNPs is promising for developing antibacterial and antibiofouling NF membranes, while their application is limited by NPs aggregation, high cost, and severe ion release. In this study, we developed novel NF membranes by integrating bimetallic AgCu nanoalloys via an in-situ reduction and coordination method facilitated by a polydopamine/polyethyleneimine (PDA/PEI) intermediate layer.
View Article and Find Full Text PDFACS Appl Mater Interfaces
December 2024
Food Science Program, University of Missouri, Columbia, Missouri 65211, United States.
The widespread use of pesticides in agriculture poses food safety and environmental risks, highlighting the need for rapid detection techniques to mitigate contamination. Surface-enhanced Raman spectroscopy (SERS) coupled with machine learning provides a powerful approach for the detection and quantification of multiple pesticides in agricultural products. This study introduces the SERSFormer-2.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!