The fluorescence of uniformly distributed chromophores in an organic solution has been used to probe the energy density profile of an optical evanescent wave, generated by total internal reflection at the solid-solution interface. The results obtained in the case of an aqueous fluorescein solution in contact with a highly polished silica surface are in good quantitative agreement with the expected exponential decay of the optical energy at the interface. It also justifies the use of the newly developed evanescent wave-induced fluorescence technique to study adsorption and depletion layers of polymer in solution close to solids walls. In such experiments the fluorescence intensity is assumed to be the Laplace transform of the concentration profile of the fluorescently labeled polymer chains. The present data validate the above assumption.
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http://dx.doi.org/10.1364/AO.28.001881 | DOI Listing |
Anal Chim Acta
March 2025
Zhejiang Key Laboratory of Advanced Optical Functional Materials and Devices, Ningbo University, Ningbo, 315211, China; Engineering Research Center for Advanced Infrared Photoelectric Materials and Devices of Zhejiang Province, Ningbo University, Ningbo, 315211, China. Electronic address:
Background: Permethrin is a pesticide used to kill insects, and once used in excess, it poses a great threat to the environment and human health, therefore, it is necessary to realize the rapid and accurate detection of permethrin. Fiber optic surface enhanced Raman scattering (SERS) probes have the advantages of small volume and can be used for remote monitoring, which have great potential for application in achieving in-situ detection of pesticide residues.
Results: Fiber taper waist (FTW) SERS probes modified by silver nanocubes-graphene oxide (Ag NCs-GO) composite structures were prepared for in situ detection of permethrin in lake water.
We propose and experimentally demonstrate what we believe to be the first mid-infrared surface plasmon resonance (SPR) fiber optic sensor using a D-shaped multimode silica optical fiber coated with a 105 nm indium tin oxide (ITO) layer. The sensor shows resonance around 2700 nm, with a refractive index sensitivity of 1065.70 nm per refractive index unit (nm/RIU) for refractive indices ranging from 1.
View Article and Find Full Text PDFBiosens Bioelectron
January 2025
Innovation Center of Functional Genomics and Molecular Diagnostics Technology of Gansu Province, Lanzhou, China.
Improving the sensitivity of biosensor has always the major challenge to measure lower detection concentration of biological samples. In this paper, a novel optical fiber surface plasmon resonance (SPR) biosensor based on TiC MXene/GNRs synergistically highly enhanced sensitivity was proposed. The TiC MXene and GNRs were coated on the optical fiber sensing probe by the electrostatic layer-by-layer (ELBL) assembly method.
View Article and Find Full Text PDFNat Commun
January 2025
Chimie du Solide et de l'Énergie, UMR 8260, Collège de France, Paris, France.
As batteries drive the transition to electrified transportation and energy systems, ensuring their quality, reliability, lifetime, and safety is crucial. While the solid electrolyte interphase (SEI) is known to govern these performance characteristics, its dynamic nature makes understanding its nucleation, growth, and composition an ambitious, yet elusive aspiration. This work employs chalcogenide fibres embedded in negative electrode materials for operando Infra-red Fibre-optic Evanescent Wave Spectroscopy (IR-FEWS), combined with Multivariate Curve Resolution by Alternating Least Squares (MCR-ALS) algorithms for spectra analysis.
View Article and Find Full Text PDFBiosens Bioelectron
January 2025
Institute of Physics, College of Natural Sciences, University of Rzeszow, Rzeszow, Poland.
Fabry disease (FD) is a rare disorder resulting from a genetic mutation characterized by the accumulation of sphingolipids in various cells throughout the human body, leading to progressive and irreversible organ damage, particularly in males. Genetically-determined deficiency or reduced activity of the enzyme (alpha - Galactosidase; α-Gal) leads to the accumulation of sphingolipids in the lysosomes of various cell types, including the heart, kidneys, skin, eyes, central nervous system, and digestive system, triggering damage, leading to the failure of vital organs, and resulting in progressive disability and premature death. FD diagnostics currently depend on costly and time-intensive genetic tests and enzymatic analysis, often leading to delayed or inaccurate diagnoses, which contribute to rapid disease progression.
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