Stable, fluorescent Ag nanoclusters were prepared in aqueous solutions of Na(+) salt of the carboxylate-rich polymer poly(acrylic acid-co-maleic acid) under brief spells of UV irradiation. The nanoclusters were nearly spherical, with diameters within 1.90 ± 0.50 nm, but displayed a prominent red edge excitation shift (REES) of fluorescence upon exciting within the visible absorption band, indicating heterogeneity of energy level distributions. Spectroscopic studies revealed that irrespective of whether the nanoclusters are excited in their UV or visible absorption bands, their fluorescence always ensues from the same manifold of emissive states, with a broad range of fluorescence lifetimes from ∼150 fs to 1 ns.
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http://dx.doi.org/10.1039/c5cp05282c | DOI Listing |
Anal Methods
January 2025
Department of Chemistry, School of Physical and Mathematical Science, Research Centre, University of Kerala, Kariavattom Campus, Thiruvananthapuram, Kerala, 695581, India.
The neuronal tau peptide serves as a key biomarker for neurodegenerative diseases, specifically, Alzheimer's disease, a condition that currently has no cure or definitive diagnosis. The methodology to noninvasively detect tau levels from body fluids remains a major hurdle for a rapid and simple diagnostic approach. Thus, developing new detection methods for sensing tau protein levels is crucial.
View Article and Find Full Text PDFTalanta
January 2025
Engineering Research Center of Nano-Geomaterials of Ministry of Education, Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan, 430074, PR China.
Pursuing nanomaterials with high fluorescence quantum yields is of great significance in the fields of bioimaging, medical diagnosis, and food safety monitoring. This work reports on orange-emitting aggregation-induced emission (AIE) copper nanoclusters (Cu NCs) integrated with blue-emitting nitrogen-doped carbon dots (N-CDs), which enables highly sensitive detection of S and Zn ions through an off-on ratiometric fluorescence method. The highly emissive Cu NCs was doped by Ce with a high quantum yield of 51.
View Article and Find Full Text PDFAnal Chem
January 2025
Research Center for Analytical Sciences, Department of Chemistry, College of Sciences, Northeastern University, Box 332, Shenyang 110819, China.
The advancement of lanthanide fingerprint sensors characterized by targeted emission responses and low self-fluorescence interference for the detection of biothiols is of considerable importance for the early diagnosis and treatment of cancer. Herein, the lanthanide "personality function tailoring" HOF composite sensor array is designed for the specific discrimination of biothiols (GSH, Cys, and Hcy) based on the activation of various luminescent molecules, such as r-AuNCs/luminol via HOF surface proximity. Lumi-HOF@Ce serves as a versatile platform for catalyzing the oxidation of -phenylenediamine (OPD) to generate yellow fluorescent oligomers, accompanied by the fluorescence attenuation of luminol.
View Article and Find Full Text PDFNat Commun
January 2025
State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun, P. R. China.
Photoluminescence is one of the most intriguing properties of metal nanoclusters derived from their molecular-like electronic structure, however, achieving high photoluminescence quantum yield (PLQY) of metal core-dictated fluorescence remains a formidable challenge. Here, we report efficient suppression of the total structural vibrations and rotations, and management of the pathways and rates of the electron transfer dynamics to boost a near-unity absolute PLQY, by decorating progressive addition of cations. Specifically, with the sequential addition of Zn, Ag, and Tb into the 3-mercaptopropionic acids capped Au nanoclusters (NCs), the low-frequency vibration of the metal core progressively decreases from 144.
View Article and Find Full Text PDFChem Asian J
January 2025
Universidad Austral de Chile, Instituto de Ciencias Químicas, CHILE.
Plasmonic materials can be utilized as effective platforms to enhance luminescent signals of luminescent metal nanoclusters (LMNCs). Both surface enhanced fluorescence (SEF) and shell-isolated nanoparticle-enhanced fluorescence (SHINEF) strategies take advantage of the localized and increased external electric field created around the plasmonic metal surface when excited at or near their characteristic plasmonic resonance. In this context, we present an experimental and computational study of different plasmonic composites, (Ag) Ag@SiO2 and (Au) Au@SiO2 nanoparticles, which were used to enhance the luminescent signal of Au nanoclusters coated with glutathione (GSH) molecule (Au25GSH NCs).
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