Near-infrared two-photon absorption and excited state dynamics of a fluorescent diarylethene (fDAE) derivative were investigated by time-resolved absorption and fluorescence spectroscopies. Prescreening with quantum chemical calculation predicted that a derivative with methylthienyl groups (mt-fDAE) in the closed-ring isomer has a two-photon absorption cross-section larger than 1000 GM, which was experimentally verified by Z-scan measurements and excitation power dependence in transient absorption. Comparison of transient absorption spectra under one-photon and simultaneous two-photon excitation conditions revealed that the closed-ring isomer of mt-fDAE populated into higher excited states deactivates following three pathways on a timescale of ca. 200 fs: (i) the cycloreversion reaction more efficient than that by the one-photon process, (ii) internal conversion into the S state, and (iii) relaxation into a lower state (S' state) different from the S state. Time-resolved fluorescence measurements demonstrated that this S' state is relaxed to the S state with the large emission probability. These findings obtained in the present work contribute to extension of the ON-OFF switching capability of fDAE to the biological window and application to super-resolution fluorescence imaging in a two-photon manner.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1007/s43630-024-00573-y | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
TCAD Simulation of Two Photon Absorption-Transient Current Technique Measurements on Silicon Detectors and LGADs.
Sensors (Basel)
December 2024
CERN, Esplanade des Particules 1, 1217 Meyrin, Switzerland.
Device simulation plays a crucial role in complementing experimental device characterisation by enabling deeper understanding of internal physical processes. However, for simulations to be trusted, experimental validation is essential to confirm the accuracy of the conclusions drawn. In the framework of semiconductor detector characterisation, one powerful tool for such validation is the Two Photon Absorption-Transient Current Technique (TPA-TCT), which allows for highly precise, three-dimensional spatially-resolved characterisation of semiconductor detectors.
View Article and Find Full Text PDFMidinfrared Cavity-Enhanced Two-Photon Absorption Spectroscopy for Selective Detection of Trace Gases.
Anal Chem
January 2025
Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China.
Detection of trace gases, such as radioactive carbon dioxide, clumped isotopes, and reactive radicals, is of great interest and poses significant challenges in various fields. Achieving both high selectivity and high sensitivity is essential in this context. We present a highly selective molecular spectroscopy method based on comb-locked, mid-infrared, cavity-enhanced, two-photon absorption.
View Article and Find Full Text PDFAn NIR-II Two-Photon Excitable AIE Photosensitizer for Precise and Efficient Treatment of Orthotopic Small-Size Glioblastoma.
Adv Mater
December 2024
School of Science and Engineering, Shenzhen Institute of Aggregate Science and Technology, The Chinese University of Hong Kong (CUHK-Shenzhen), Shenzhen, Guangdong, 518172, P. R. China.
The existence of residual small-size tumors after surgery is a major factor contributing to the high recurrence rate of glioblastoma (GBM). Conventional adjuvant therapeutics involving both chemotherapy and radiotherapy usually exhibit unsatisfactory efficacy and severe side effects. Recently, two-photon photodynamic therapy (TP-PDT), especially excited by the second near-infrared (NIR-II) light, offers an unprecedented opportunity to address this challenge, attributed to its combinational merits of PDT and TP excitation.
View Article and Find Full Text PDFTwo-photon brightness of NIR-emitting, atomically precise DNA-stabilized silver nanoclusters.
Chem Sci
December 2024
Institute of Advanced Materials, Wroclaw University of Science and Technology Wrocław Poland
Near-infrared (NIR) emitters with high two-photon absorption (2PA) cross-sections are of interest to enable imaging in the tissue transparency windows. This study explores the potential of DNA-stabilized silver nanoclusters (Ag -DNAs) as water-soluble two-photon absorbers. We investigate 2PA of four different atomically precise Ag -DNA species with far-red to NIR emission and varying nanocluster and ligand compositions.
View Article and Find Full Text PDFFRET-based mesoporous organosilica nanoplatforms for and anticancer two-photon photodynamic therapy.
J Mater Chem B
December 2024
ICGM, University of Montpellier, UMR-CNRS 5253, 34293 Montpellier, France.
We report the synthesis of multifunctional periodic mesoporous organosilica nanoparticles (PMO NPs) with substantial two-photon absorption properties and targeting capability for two-photon excitation fluorescence (TPEF) and photodynamic therapy (TPE-PDT). Prepared using an adapted sol-gel synthesis, the nanoplatforms integrated two silylated chromophores in their three-dimensional matrix to maximize non-radiative Förster resonance energy transfer from a high two-photon absorption fluorophore donor to a porphyrin derivative acceptor, leading to an enhanced generation of reactive oxygen species. Combinations of biodegradable and non-biodegradable bis(triethoxysilyl)alkoxysilanes were employed for the synthesis of the NPs, and the corresponding photophysical studies revealed high efficiency levels of FRET.
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!