AI Article Synopsis
- A new technique allows for the measurement of fluorophore excited state lifetimes in murky environments without collecting fluorescence, using a pump-probe method with laser pulses.
- The method captures transient absorption through photoacoustic signals, which helps determine the excited state lifetime by analyzing changes over time.
- Validated against conventional measurements, the technique shows potential for applications in tissue oxygen imaging and tracking molecular interactions in biology.
Article Abstract
A new method is developed to perform local measurements of fluorophore excited state lifetimes in turbid media without collecting the fluorescence emission. The method is based on a pump-probe approach where a first laser pulse excites the dye and then a second laser pulse is used for photoacoustic probing of the transient absorption. The photoacoustic response generated by the probe pulse is recorded by an ultrasound receiver. Repeating the measurement for increasing pump-probe time delays yields a series of photoacoustic signals that are used to extract the lifetime of the excited state. The method is validated by measuring the lifetime of an oxygen sensitive dye solution at different concentrations of dissolved oxygen. The dye is pumped with a 532-nm pulsed laser and the transient absorption at 740 nm is probed using a second pulsed laser system. The photoacoustic-based results are in close agreement with those obtained from time-dependent fluorescent measurements. The method can be extended to photoacoustic lifetime imaging by using a receiver array instead of a single receiver. Potential applications of this method include tissue oxygen imaging for cancer diagnostics and mapping molecular events such as resonant energy transfer and ion collisions in a biological environment.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1117/1.2927466 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Capturing the Elusive Curve-Crossing in Low-Lying States of Butadiene with Dressed TDDFT.
J Phys Chem Lett
January 2025
Department of Physics, Rutgers University, Newark 07102, New Jersey, United States.
A striking example of the need to accurately capture states of double-excitation character in molecules is seen in predicting photoinduced dynamics in small polyenes. Due to the coupling of electronic and nuclear motions, the dark 2Ag state, known to have double-excitation character, can be reached after an initial photoexcitation to the bright 1Bu state via crossings of their potential energy surfaces. However, the shapes of the surfaces are so poorly captured by most electronic structure methods, that the crossing is missed or substantially mis-located.
View Article and Find Full Text PDFTheoretical Understanding of Photoluminescence and Singlet Oxygen Quantum Yields in a Few Halogenated Fluorescein Dyes.
Chem Asian J
December 2024
Department of Chemistry, Indian Institute of Technology Tirupati, Tirupati, A.P 517619, India.
Visible-light absorbing metal-free organic dyes are of increasing demand for various optoelectronic applications because of their great structure-function tunability through chemical means. Several dyes also show huge potential in triplet photosensitization, generating reactive singlet oxygen. Understanding the structure-property relationships of many well-known fluorescein dyes is of paramount importance in designing next-generation energy efficient dyes, which is currently limited.
View Article and Find Full Text PDFMolecular and cellular targets of GABAergic anesthetics in the mesopontine tegmentum that enable pain-free surgery.
Pain
December 2024
Department of Cell and Developmental Biology, Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel.
The mesopontine tegmental anesthesia area (MPTA) is a focal brainstem locus which, when exposed to GABAergic agents, induces brain-state transitioning from wakefulness to unconsciousness. Correspondingly, MPTA lesions render animals relatively insensitive to GABAergic anesthetics delivered systemically. Using chemogenetics, we recently identified a neuronal subpopulation within the MPTA whose excitation induces this same pro-anesthetic effect.
View Article and Find Full Text PDFResolving Artifacts and Improving the Detection Limit in Circular Differential Scattering Measurement of Chiral and Achiral Gold Nanorods.
ACS Nano
January 2025
Jiangsu Key Laboratory of Frontier Material Physics and Devices, School of Physical Science and Technology, Soochow University, Suzhou, Jiangsu 215006, China.
Circular differential scattering (CDS) spectroscopy has been developed as a powerful method for the characterization of the optical activity of individual plasmonic nanostructures and their complexes with chiral molecules. However, standard measurement setups often result in artifacts that have long raised concerns on the interpretation of spectral data. In fact, the detection limit of CDS setups is constrained by the high level of artifacts, to ±10%.
View Article and Find Full Text PDFDynamic Phosphorescence Behavior of Carbene-Metal-Amide Complexes from the Perspective of Excited State Modulation.
Angew Chem Int Ed Engl
January 2025
Beijing Institute of Technology, School of Chemistry and Chemical Engineering, CHINA.
Carbene-metal-amide (CMA) complexes have diverse applications in luminescence, imaging and sensing. In this study, we designed and synthesized a series of CMA complexes, which were subsequently doped into a PMMA host. These materials demonstrate light-induced dynamic phosphorescence, attributed to their long intrinsic triplet state lifetime (τP,int, in the μs-ms scale), high intersystem crossing (ISC) rate constant (kISC, up to 107 s-1), and bright phosphorescence.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!