A5054861756- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Advanced Fluorescence Microscopy Techniques
- Luminescence and Fluorescent Materials
- Photochemistry and Electron Transfer Studies
- Photosynthetic Processes and Mechanisms
- Photoreceptor and optogenetics research
- Click Chemistry and Applications
- Luminescence Properties of Advanced Materials
- Molecular Sensors and Ion Detection
- Advanced biosensing and bioanalysis techniques
- Advanced Biosensing Techniques and Applications
- Spectroscopy and Quantum Chemical Studies
- Porphyrin and Phthalocyanine Chemistry
- Crystallography and molecular interactions
- Nanocluster Synthesis and Applications
- Photochromic and Fluorescence Chemistry
- Gold and Silver Nanoparticles Synthesis and Applications
- Free Radicals and Antioxidants
- Microwave Dielectric Ceramics Synthesis
- Perovskite Materials and Applications
- Chemical Synthesis and Analysis
- Advanced Nanomaterials in Catalysis
- Cancer Research and Treatments
- Radiation Detection and Scintillator Technologies
Saarland University
2015-2025
Sejong University
2018-2022
Geophysical Laboratory
2011
Lawrence Berkeley National Laboratory
2005
Ludwig-Maximilians-Universität München
1998-2004
Center for NanoScience
2000-2004
University of California, Berkeley
2003
Leibniz-Institute for New Materials
1998
Fluorescent noble metal (Au, Ag) nanoclusters have been biolabeled to bovine serum albumin (BSA) by wet chemistry. Spectroscopic and fluorescence investigations relate the role of pH nature reducing agent size oxidation state clusters. Blue-emitting (λ = 450 nm) small gold (eight atoms) prepared at 8 weakly bonded BSA grow higher form red-emitting 690 bigger clusters (25 covalently via sulfur group. X-ray photoelectron spectroscopy (XPS) measurements indicate presence Au(I) only for big...
Gold nanoclusters prepared with a controlled amount of Ag exhibit intense fluorescence quantum yield ~16% and "quasi-monoexponential" long lifetime >200 ns. Characterization the luminescent probes indicates high photostability easy detection in cells. Additionally, enhancement presence proteins was found.
In single-molecule applications, the photostability of fluorescent molecules is a key parameter. We apply fluorescence correlation spectroscopy to compare four fluorescein and borondipyrromethene (BODIPY) dyes similar structure but different triplet yields. The latter class are more stable. kinetic analysis the, diffusion photobleaching treated as competitive processes. Corrections, which account for saturation experimental artefacts, achieved solely by using data. Photobleaching found occur...
In this paper we describe the synthesis and optimisation of a new family fluorescent core–shell nanoparticle using protein-stabilised gold nanoclusters. Fluorescent nanoclusters (<2 nm) entrapped in bovine serum albumin (BSA) protein were loaded 100 nm-silica with an optimal concentration 3% (w/w). These nanoparticles kept fluorescence properties metal clusters high Stokes shift emission near infrared region (λ = 670 nm). They fully characterized showed monodispersity stability over more...
Steady-state and time-resolved techniques were employed to study the excited-state proton-transfer (ESPT) rate of two newly synthesized 8-hydroxy-1,3,6-pyrenetrisulfonate (pyranine, HPTS) derived photoacids in three protic solvents, water, methanol ethanol. The ESPT constant kPT tris(1,1,1,3,3,3-hexafluoropropan-2-yl)-8-hydroxypyrene-1,3,6-trisulfonate, 1a, whose pKa* ∼ −4, ethanol is 3 × 1011 s−1, 8 109 s−1 5 respectively....
New types of fluorescent platinum nanoclusters (λmax.= 570 nm) have been synthesized using glutathione for ligand etching. These are mainly in the oxidation state PtI (90%) exhibiting an intense fluorescence signal (QY∼17%) yellow region and lead to formation blue-emitting species a long etching time process.
Focus on chemical transitions: Epoxidation of a double bond in conjugation to fluorescent dye was studied at single-molecule level. Direct observation oxirane formation, indicated as spectral shift from substrate product state, revealed an alternative reaction pathway for the epoxidation reaction. As service our authors and readers, this journal provides supporting information supplied by authors. Such materials are peer reviewed may be re-organized online delivery, but not copy-edited or...
Photoacidity is frequently found in aromatic alcohols where the equilibrium dissociation constant increases by some orders of magnitude upon electronic excitation. In this study we investigated solvatochromism a family recently synthesized super-photoacids and their methylated counterparts based on pyrene. The chemical similarity these molecules one hand differing photoacidity with pKa* values between -0.8 -3.9 other allow for gaining insights into mechanisms contributing to excited-state...
The reaction of terrylene in p‐terphenyl with molecular oxygen is reinvestigated by TIRF‐microscopy λexc = 488 nm or 561 and nm. A similar range fluorescent products obtained under both experimental conditions a quantum yield Φr > 10‐7 for those molecules which undergo the photoreaction. majority these oxygen‐susceptible reacts via an electronically relaxed, dark intermediate, presumably endoperoxide, lifetime <toff> ~ 20 s. From this time constant, activation energy EA < 0.8 eV...
Abstract Deletion of the short arm chromosome 1 (1p) increases recurrence rates in meningiomas by up to 33%, regardless tumor grade, correlating with absence intracellular alkaline phosphatase enzyme activity. Current screening methods for 1p deletion like fluorescence situ hybridization (FISH) and loss heterozygosity (LOH) analysis are resource-intensive. This study evaluated AlkaPhos, a novel fluorescent probe, detecting meningioma cells compared findings FISH, LOH, histochemical analysis....
Structurally driven properties of hybrid materials are a fascinating feature metal–organic framework (MOF) that can serve as hosts for various responsive dye molecules. In particular, the formation aggregates and related shift emission fluorophors be tuned function pore confinement. this work, fluorosolvatochromic methylated photoacid tris(2,2,2-trifluoroethyl) 8-methoxypyrene-1,3,6-trisulfonate (MePhos) free 8-hydroxypyrene-1,3,6-trisulfonate (Phos) were inserted into MOF scaffolds,...
Starch was oxidized with TEMPO for the synthesis of water-soluble copolymers glucuronic acid and glucose. The carboxylate groups these were conjugated pteroic as cell-specific ligand targeting to cancer cells. Stable spherical nanoparticles (NPs) formulated mixing aqueous solutions anionic a cationic thioether β-cyclodextrin (β-CD). Particle size distributions NPs investigated DLS function charge ratio constituents. smallest most uniform particles diameter about 130 nm generated at...
A principal objective in life sciences is the visualization of biochemical processes. Fluorescence‐based techniques are widely used to demonstrate transport relevant substances across cellular membranes. In this paper we report a novel noninvasive, real‐time fluorescence lifetime imaging microscopy method for visualizing uptake and release divalent copper ions (Cu 2+ ) vivo . For purpose, employed green fluorescent protein (GFP) form able change its upon Cu binding. We that technique...
Abstract Gold nanocluster (AuNC) synthesis using a well‐distinguished polymer for nanoparticle‐mediated drug delivery paves the way developing efficient theranostics based on pharmaceutically accepted materials. Gelatin‐stabilized AuNCs are synthesized and modified by glutathione tuning emission spectra. Addition of silver ions enhances fluorescence, reaching also high quantum yield (26.7%). A simplified model can be proposed describing nanoclusters' properties–structure relationship X‐ray...