Luminescence最新文献

Photodynamic antibacterial fabrics are crucial for public health via efficient, durable antimicrobial protection. Herein, two series of triphenylamine (TPA)-based aggregation-induced emission (AIE)-active cationic fluorescent dyes were rationally designed and synthesized, integrating acceptor engineering and alkyl-chain engineering for textile functionalization. Based on acceptor engineering, TPPy-C2 with cationic pyridine exhibited the highest fluorescence intensity and reactive oxygen species (ROS) yield. Furthermore, based on alkyl-chain engineering, TPPy-C8 with octyl showed the best antibacterial activity against both Gram-negative (E. coli) and Gram-positive (S. aureus) bacteria. Acrylic fibers were dyed using AIE cationic dyes to prepare dyed fabrics. Compared with commercial Basic orange 22, the efficient generation of ROS and the optimized alkyl chain length of TPPy-C8-F synergistically enhanced both bacterial adhesion and ROS-mediated damage, which exhibited excellent antibacterial activity. Not only does TPPy-C8-F have satisfactory wash fastness and rubbing fastness, but its mechanical properties remain almost unchanged after being exposed to light for 30 min. This work not only provides a new perspective on the construction of cationic dyes with photodynamic antibacterial properties but also provides a promising strategy for the fabrication of multifunctional antibacterial textiles.

Development of fluorescent chemosensors for Al³⁺ is one of the important research areas as the presence of the cation is responsible for many health issues. The study presents the development and analysis of a novel Al³⁺ detecting compound, 4-(2-(4-hydroxy-3-((quinolin-3-ylimino)methyl)phenyl)propan-2-yl)-2-((quinolin-3-ylimino)methyl)phenol (abbreviated as H₂P). The probe was obtained by a simple condensation of bisphenol A dialdehyde and 3-amino quinoline (1:2 ratio) in methanol under mild conditions. A distinct color change was observed in the bare eye under UV light in the presence of Al³⁺, whereas other metal ions remained unresponsive. The fluorescence probe demonstrates a remarkable enhancement in fluorescence intensity, specifically a 29-fold increase at 466 nm, when exposed to Al³⁺. This phenomenon has been attributed to two mechanisms: the chelation enhanced fluorescence (CHEF) effect and the inhibition of C=N isomerization. The probe exhibits high sensitivity toward Al³⁺, with a detection limit of 1.48 × 10^-7 M. Furthermore, it forms a complex with the cation in a 1:2 ratio (ligand to metal), characterized by an association constant of 3.30 × 10⁴ M^-1. The application of H₂P demonstrated efficacy in detecting Al³⁺ within water samples.

In this study, non-stoichiometric molybdenum oxide/prussian blue nanocomposites (MoO_3-x/PB NCs) were synthesized via a simple one-pot method. The MoO_3-x/PB NCs can catalyze the conversion of dissolved oxygen into reactive oxygen species (ROS), generating chemiluminescence (CL) without additional oxidants. Meanwhile, compared with the original alkaline luminol solutions, it significantly enhances the CL signal, with an increase of over 1000-fold. Utilizing the CL intensity-quenching capability of HQ, a highly sensitive CL sensor has been developed. The linear range was 10-500 nmol·L^-1 and the detection limit (LOD) was 1 nmol·L^-1, along with excellent selectivity and anti-interference capability. At the same time, this study not only provided a new strategy for detecting HQ in lake and tap water but also expanded the application potential of MoO_3-x/PB NCs in CL analysis.

In this study, a kind of red-emitting carbon dots (R-CDs) was synthesized by solvothermal treatment of terephthalic acid (TPA) and 5-amino-1,10-phenanthroline (Aphen) as precursors in N, N-dimethylformamide (DMF). Comprehensive characterizations demonstrated that the R-CDs were uniform spheres with an average diameter of 2.56 nm and exhibited red fluorescence at 615 nm under 555-nm excitation. The R-CDs could form non-fluorescent ground-state aggregates with Cu²⁺, resulting in an increase in the average particle size to 3.70 nm. The aggregation also caused a significant fluorescence quenching through a static mechanism, concomitant with a change of the R-CDs solution. Consequently, a fluorescence-colorimetric dual-mode sensor was constructed for Cu²⁺ detection, with a LOD of 90 nM in the fluorescence mode and 0.73 μM in the colorimetric mode. Based on the distinct fluorescence response of R-CDs, smartphone-assisted visual detection of Cu²⁺ was also achieved in real samples. This approach demonstrates advantages of convenience, time efficiency, and low cost, providing a new strategy for in situ detection of heavy metals.

Cysteine (Cys), as one of the essential amino acids in humans, plays critical roles in numerous physiological processes, and its abnormal levels are closely associated with various diseases. Therefore, rapid and sensitive detection of Cys is of great significance for early disease diagnosis and mechanistic studies. In this work, we developed a novel near-infrared (NIR) fluorescent "turn-on" probe, NA-XL, featuring a large Stokes shift (177 nm) for highly efficient detection of the biothiol Cys. The probe incorporates a naphthalimide fluorophore and an acrylate group that serves as both the Cys recognition site and fluorescence quencher. The fluorescence quenching of NA-XL is predominantly governed by strong low-frequency vibrations. Upon selective reaction with Cys, this vibration-mediated quenching process is effectively suppressed, leading to a pronounced NIR fluorescence emission at 729 nm. The probe demonstrates excellent selectivity and sensitivity, achieving a low detection limit (LOD) of 10.7 nM. Furthermore, NA-XL exhibits outstanding responsiveness to both exogenous and endogenous Cys in cellular imaging, enabling real-time monitoring of Cys dynamics. These findings highlight its potential for biomedical research applications.

Polyvinylpyrrolidone (PVP) and cysteine (Cys) double-ligand-modified copper nanoclusters (PVP-Cys CuNCs) were synthesized by a one-pot method. The addition of Cys can protect copper nanoclusters (CuNCs) more effectively and enhance its fluorescence intensity, compared with the single-ligand-modified PVP CuNCs; the double-ligand-modified PVP-Cys CuNCs showed higher fluorescence intensity and sensing ability. Based on the internal filtration and dynamic quenching effect of berberine (BBR) on PVP-Cys CuNCs, a novel, simple, and sensitive method for BBR detection has been established. This method exhibits a good linear response to BBR within the linear range of 1.09 × 10^-7-4.26 × 10^-6 mol · L^-1, and with a limit of detection (LOD) of 3.67 × 10^-8 mol · L^-1. It has been successfully applied to the determination of BBR in practical pharmaceutical samples.

This study introduces a novel approach for enhancing the inherent native fluorescence of pranoprofen, a nonsteroidal anti-inflammatory drug (NSAID), commonly used to treat allergic conjunctivitis. The fluorescence was significantly amplified when pranoprofen was encapsulated within the hydrophobic cavity of β-cyclodextrin, which provided a favorable microenvironment that stabilized its protonated form. The enhanced fluorescence intensity was measured at 404 nm following excitation at 273 nm with a large Stokes shift of around 130 nm. The method was validated following ICH guidelines and demonstrated excellent linearity over a concentration range of 0.10-6.0 μg/mL, with a correlation coefficient of 0.9999 and a low limit of detection (LOD) of 0.034 μg/mL. The proposed method was effectively applied for the analysis of pranoprofen in ophthalmic solutions and aqueous humor, yielding recoveries ranging from 98.9 to 101.1%. Furthermore, multifaceted sustainability assessment tools confirmed the method's eco-sustainability. This analytical strategy offers a reliable, rapid, and eco-friendly solution for the routine analysis of pranoprofen in pharmaceutical and clinical analysis.

In this study, CuO nanoparticles (NPs) were synthesized via a simple precipitation method and characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and energy-dispersive X-ray spectroscopy (EDS). The CuO NPs exhibited high crystallinity with a monoclinic phase and an average crystalline size of 22 nm. UV-visible spectroscopy revealed an excitonic absorption peak at 251 nm and a bandgap of 3.78 eV, while photoluminescence (PL) studies showed a distinct emission peak at 379 nm, attributed to radiative recombination and defects in the NPs structure. The interaction between CuO NPs and NB-690 dye was explored through UV-visible and fluorescence spectroscopy, showing enhanced absorption and fluorescence quenching upon complex formation. The apparent association constant (K_app) was determined to be 1 × 10⁶ M^-1, with a low limit of detection (12 nM). Stern-Volmer analysis revealed a binding constant of 6.21 × 10⁵ M^-1 and a binding site value of 1.7 in the excited state. These results highlight the potential of CuO NPs for applications in environmental monitoring, biomedical imaging, and drug delivery, demonstrating their ability to modulate light absorption and fluorescence in complex biological and chemical systems.

Three novel Schiff base chemosensors (HZ-1, HZ-2, and HZ-3) were synthesized by condensing 4-hydroxy-[1,1'-biphenyl]-3-carbaldehyde with distinct hydrazine derivatives: (Z)-(anthracen-9-ylmethylene)hydrazine, (Z)-(pyren-1-ylmethylene)hydrazine, and (Z)-4-(hydrazonomethyl)-N,N-diphenylaniline. Structural variation was confined to the hydrazine moiety, enabling a systematic investigation of its influence on photophysical and sensing properties. UV-Vis absorption and fluorescence studies revealed marked differences in optical behavior, with HZ-1 and HZ-3 chemosensors showing significant fluorescence enhancement upon selective metal ion binding as compared with HZ-2. The limit of detection (LOD) for each sensor was in the micromolar range, confirming their high sensitivity. Job's plot analysis indicated a predominant 2:1 ligand-to-metal stoichiometry. Complementary density functional theory (DFT) calculations provided insights into frontier molecular orbitals and electron density distributions, rationalizing the observed spectral variations. Overall, this study demonstrates how precise modification of the hydrazine fragment can tailor the electronic environment and sensing performance of Schiff bases, offering valuable design strategies for efficient fluorescent metal ion chemosensors.

Fibroblast activation protein-α (FAP-α) is a crucial biomarker for pancreatic cancer, yet developing activatable near-infrared (NIR) fluorescent probes for its real-time imaging faces challenges in achieving high signal-to-background ratios and specificity. Here, we present ZGP-D, a novel FAP-α-activated NIR probe designed to overcome these limitations. ZGP-D integrates a DDAO fluorophore with a FAP-α-specific Cbz-Gly-Pro peptide, creating an efficient intramolecular charge transfer (ICT) quenching mechanism that ensures a minimal background signal. Upon specific enzymatic cleavage by FAP-α, the probe exhibits a robust > 40-fold fluorescence turn-on at 657 nm, demonstrating exceptional sensitivity with a detection limit of 0.024 μg/mL and superior selectivity over various biological interferents. ZGP-D successfully visualized endogenous FAP-α in living cells, clearly distinguishing high-expression pancreatic cancer cells (BXPC-3) from low-expression cells. Furthermore, in a BXPC-3 xenograft mouse model, local administration of ZGP-D enabled high-contrast tumor imaging, achieving a tumor-to-normal tissue signal ratio of 4.2. This work establishes ZGP-D as a highly sensitive and specific molecular tool for monitoring FAP-α activity, highlighting its significant potential for advancing cancer diagnostics and fluorescence-guided surgery.