Related Experiment Video
Updated: Jun 22, 2026
06:42
Plasmonic Photothermal Cancer Therapy: Nanoparticle-embedded Tumor-tissue-mimicking Phantoms for Visualizing Photothermal Temperature Distribution
Published on: May 9, 2025
Fluorescence quenching by polystyrene microspheres in UV-visible and NIR tissue-simulating phantoms
Optics Express
|June 17, 2009
Summary
Polystyrene microspheres in tissue phantoms can reduce fluorescence by quenching. This effect, dependent on microsphere and fluorophore concentration, requires fluorescence lifetime measurements for accurate optical studies.
Area of Science:
- Biomedical Optics
- Photonic Applications
- Materials Science
Background:
- Tissue-simulating phantoms are crucial for controlled studies of light propagation.
- Polystyrene microspheres are commonly used as scatterers in these phantoms.
- Potential interactions between microspheres and fluorophores are not fully characterized.
Purpose of the Study:
- To investigate the impact of polystyrene microspheres on fluorophore quantum yield in tissue-simulating phantoms.
- To quantify the collisional quenching effect of microspheres on different fluorophores (fluorescein and IR125).
- To determine the relationship between microsphere concentration, fluorophore concentration, and quenching efficiency.
Main Methods:
- Fabrication of tissue-simulating phantoms with varying concentrations of polystyrene microspheres and fluorophores.
- Utilized UV-visible (fluorescein) and near-infrared (IR125) fluorophores.
- Performed fluorescence lifetime measurements to assess quenching effects.
- Analyzed data using the Stern-Volmer relation.
Main Results:
- Polystyrene microspheres were found to reduce fluorophore quantum yield via collisional quenching.
- Quenching efficiency correlated with the concentration ratio of fluorophores to microspheres.
- Measured fluorescence lifetime decreases of 10-35% for fluorescein and 20% for IR125.
- Results align with the Stern-Volmer model, indicating decreased intrinsic excited-state lifetime.
Conclusions:
- Polystyrene microspheres can significantly impact fluorescence measurements in tissue phantoms.
- Collisional quenching by microspheres must be considered in quantitative fluorescence studies.
- Simultaneous fluorescence lifetime measurements are essential to differentiate quenching from absorption/scattering losses.
Related Concept Videos
01:25Fluorescence and Phosphorescence: Instrumentation
Fluorometers and spectrofluorometers are two types of instruments used for measuring molecular fluorescence. These instruments differ in how they select excitation and emission wavelengths and the type of light sources they utilize. Fluorometers use absorption interference filters to choose excitation and emission wavelengths. The excitation source in a fluorometer is typically a low-pressure mercury vapor lamp that emits intense lines distributed throughout the ultraviolet and visible regions.
01:14Photoluminescence: Applications
Photoluminescence offers a wide range of applications due to its inherent sensitivity and selectivity. This technique allows for both direct and indirect analyses of the analyte. Direct quantitative analysis is possible when the analyte exhibits a favorable quantum yield for fluorescence or phosphorescence. However, an indirect analysis may be feasible if the analyte is not fluorescent or phosphorescent, or if the quantum yield is unfavorable. Indirect methods include reacting the analyte with...
01:26Variables Affecting Phosphorescence and Fluorescence
Fluorescence and phosphorescence are essential phenomena in fields like analytical chemistry, biological imaging, and materials science, where they detect molecular properties and visualize cellular structures. Understanding the variables that influence these luminescent behaviors is crucial for maximizing accuracy and efficiency in their applications. These variables can broadly be grouped into chemical structure, solvent properties, and external conditions, each playing a distinct role in...
01:23Photoluminescence: Fluorescence and Phosphorescence
Photoluminescence is a process where a molecule absorbs light energy and re-emits it in the form of light. This phenomenon occurs when a substance absorbs photons, promoting its electrons to higher energy level excited states, followed by a relaxation process in which the electrons return to their original ground state energy levels and emit light. Photoluminescence is widely observed in various materials, including semiconductors, and organic and inorganic compounds.
A pair of electrons in a...
A pair of electrons in a...