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Tetraphenylethylene (TPE), a typical luminogen with aggregation-induced emission (AIE) features, has been widely used to prepare AIE fluorescent materials. In this study, TPE-functionalized polydimethylsiloxane (n-TPE-AP-PDMS) was successfully synthesized by attaching TPE to polydimethylsiloxane via aza-Michael addition. The introduction of polydimethylsiloxane to TPE had no obvious effect on photophysical properties. Intriguingly, n-TPE-AP-PDMS exhibited two opposite fluorescence emission behaviors in different systems: aggregation-induced quenching (ACQ) behavior in a tetrahydrofuran/water mixture and typical AIE phenomenon in a tetrahydrofuran/hexane mixture. This unexpected transition from ACQ to AIE can be attributed to a twisted intramolecular charge-transfer effect and flexible aminopropyl polydimethylsiloxane. n-TPE-AP-PDMS was further used as a fluorescent probe to detect nitrobenzene and it showed high quenching efficiency. Moreover, the n-TPE-AP-PDMS film showed high reversibility so that the quenching efficiency remained constant after five cycles. This work can provide a deeper understanding of AIE behavior and guidance to develop a new AIE polymer for chemosensors with high performance.
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http://dx.doi.org/10.3390/polym13183046 | DOI Listing |
J Phys Chem Lett
September 2025
Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, Oregon 97331, United States.
Carbon dots (CDs) represent a new class of nontoxic and sustainable nanomaterials with increasing applications. Among them, bright and large Stokes-shift CDs are highly desirable for display and imaging, yet the emission mechanisms remain unclear. We obtained structural signatures for the recently engineered green and red CDs by ground-state femtosecond stimulated Raman spectroscopy (FSRS), then synthesized orange CDs with similar size but much higher nitrogen dopants than red CDs.
View Article and Find Full Text PDFRev Sci Instrum
September 2025
National Centre for Physics (NCP), Islamabad, Pakistan.
Time-resolved data acquisition is crucial for compositional analysis using Laser-Induced Breakdown Spectroscopy (LIBS). It can be managed by adjusting the delay time and gate width of the spectrometer. This study describes the compositional analysis of molybdenum (Mo) ore utilizing charge coupled device (CCD) and intensified charge-coupled device (ICCD) based LIBS systems.
View Article and Find Full Text PDFAdv Mater
September 2025
State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China.
Helicene-based circularly polarized luminescence (CPL) materials suffer from severely low color purity in circularly polarized organic light-emitting diodes (CP-OLEDs). Here, a novel molecular engineering strategy is introduced by replacing helicene containing continuous fused benzene rings with a multiple resonance (MR) framework comprising discontinuous fused benzene rings. This approach effectively suppresses high-frequency C─C bond stretching vibrations and enhances short-range charge transfer, enabling high color purity, CPL activity, and efficient thermally activated delayed fluorescence (TADF).
View Article and Find Full Text PDFJ Biomed Opt
September 2025
Fraunhofer Institute for Microelectronic Circuits and Systems IMS, Duisburg, Germany.
Significance: The spatial and temporal distribution of fluorophore fractions in biological and environmental systems contains valuable information about the interactions and dynamics of these systems. To access this information, fluorophore fractions are commonly determined by means of their fluorescence emission spectrum (ES) or lifetime (LT). Combining both dimensions in temporal-spectral multiplexed data enables more accurate fraction determination while requiring advanced and fast analysis methods to handle the increased data complexity and size.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
September 2025
Shaanxi Key Laboratory of New Concept Sensors and Molecular Materials, Key Laboratory of Applied Surface and Colloids Chemistry, Department of Chemistry and Chemical Engineering, ShaanXi Normal University, Xi'an, 710062, P.R. China.
Rhodamine derivatives exhibiting inverted open-closed form fluorescence behavior redefines conventional photochemical paradigms while illuminating new structure-property relationships and fascinating application potentials. Herein, we report a donor-acceptor engineering strategy that activates closed form emission in rhodamines, achieving unprecedented Stokes shifts (>280 nm) while overcoming aggregation-caused quenching. The new class of rhodamines with inverted open-close form emission behavior are created through simultaneous substitution of N,N-diethyl groups with indole (donor) and conversion of spiro-lactam to benzene sulfonamide (acceptor).
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