Luminescence最新文献

This work presents a comprehensive numerical study on a lead-free, tin-based perovskite photodetector (PPD) designed for low-light biomedical sensing applications. Using CH₃NH₃SnBr₃ as the active absorber layer, we model a device architecture comprising FTO/CdZnS/CH₃NH₃SnBr₃/Spiro-OMeTAD/Au, optimizing key parameters through combined SCAPS-1D and COMSOL Multiphysics simulations. We systematically investigate the influence of absorber thickness, defect density, donor doping, electric field distribution, series and shunt resistance, and interface properties to maximize optoelectronic performance. The optimized PPD achieves a peak responsivity of 0.55 A/W and a detectivity of 9.7 × 10¹⁴ Jones within the red-light spectral window (680–790 nm), demonstrating enhanced charge carrier lifetimes and effective interfacial charge extraction. These results highlight the potential of CH₃NH₃SnBr₃ as an eco-friendly alternative to lead-based perovskites, advancing the development of high-sensitivity, low-illumination photodetectors for biomedical imaging and diagnostics.

Silver is a highly toxic heavy metal pollutant. Its excessive release into the environment and long-term accumulation in living organisms can have serious impacts on ecosystems and human health. Therefore, developing precise detection methods for Ag⁺ is crucial for environmental monitoring and biomedical applications. Currently, common peptide fluorescent probes neglect the effects of self-assembly of probe molecules to form nanoparticles. In this study, we focused on this factor and systematically adjusted the hydrophilicity of peptides to design and synthesize three Ag⁺ responsive fluorescent probes: DNSCI-SPPW, DNSCI-APGYHA, and DNSCI-GPTHC. Among them, DNSCI-APGYHA exhibits stable morphological characteristics in solution and better selectivity for Ag⁺. Additionally, this probe shows a lower detection limit (19 nM) and stronger resistance to interference. Notably, DNSCI-APGYHA demonstrates good cell permeability and low cytotoxicity, and has been successfully applied for fluorescent imaging detection of Ag⁺ in CT26 cells.

We constructed a single-component nanotheranostic platform by assembling IDIC-Phc6, a photosensitizer with an acceptor–donor–acceptor structure, with DSPE-PEG-NH₂. The IDIC-Phc6 nanoparticles (NPs) synchronized the following therapeutic and diagnostic functions upon single-wavelength excitation at 635 nm: (1) high-contrast tumor imaging through strong near-infrared (NIR) fluorescence emission, (2) localized hyperthermia due to high photothermal conversion efficiency (43.5%), and (3) activation of type I/II photodynamic therapy that generates both singlet oxygen (Φ_Δ = 48.7%) and superoxide anions to overcome tumor hypoxia. In vitro experiments confirmed the biocompatibility of IDIC-Phc6 NPs in the absence of photoactivation, whereas the combination of the NPs and laser irradiation induced apoptosis in tumor cells via mitochondrial membrane depolarization and triggered immunogenic cell death (ICD). Furthermore, IDIC-Phc6 NPs achieved precise tumor imaging in vivo through strong NIR fluorescence, significantly inhibited tumor growth via phototherapeutic effects, and remodeled the immune microenvironment. This single-component platform integrating theranostics, dual-modal synergistic therapy, and immune activation provides an innovative solution to overcome the barriers of the tumor microenvironment and enable clinical translation of precision phototherapy.

The current study utilizes Box–Behnken design (BBD) to optimize zinc oxide (ZnO) nanoparticles biogenic synthesis from Centratherum punctatum leaf extract. The study also explores the biogenically generated zinc oxide nanoparticles from C. punctatum at optimized conditions evaluated for anti-oxidant, antimicrobial, and photocatalytic dye degradation properties. Optimized parametric conditions for zinc oxide nanoparticles from C. punctatum were zinc nitrate (50 mM), incubation time (24 h), temperature (75°C), and pH (8). Biogenic ZnO NP characterization revealed that hexagonal wurtzite morphology was 50–70 nm in size, showing characteristic absorption at 302 nm. Further, biogenically synthesized zinc oxide nanoparticles from C. punctatum screened for anti-oxidant properties using the DPPH spectrophotometric method revealed that ZnO NP possesses an equipotent IC₅₀ value as the reference standard compared with the C. punctatum plant leaf extract IC₅₀ value. Antimicrobial screening of ZnO NP shows its maximal zone of inhibition against clinical pathogens compared with standard tetracycline antibiotic. ZnO NP showed 94% degradation efficiency for rhodamine B dye under photocatalytic degradation condition in 100 min incubation. Biogenically synthesized ZnO nanoparticles from C. punctatum leaf extract showed excellent antimicrobial and photocatalytic dye degradation useful for both medical and environmental applications.

The affordable and readily available 3d metal copper with collagen as a stabilizing agent demonstrates the effective production of fluorescent copper nanoclusters. A facile one-pot green approach has been developed to obtain collagen-stabilized fluorescent copper nanoclusters (Collagen-CuNCs). The fluorescent Collagen-CuNCs were characterized by different methods, such as HR-TEM, FT-IR, XPS, UV–Vis, and fluorescence spectroscopy. The metal ions selectivity of Collagen-CuNCs was examined in an aqueous medium by adding Ca²⁺, Hg²⁺, Cd²⁺, Pb²⁺, Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺, Fe³⁺, Cr³⁺, Al³⁺, and Fe²⁺ ions. Ferric ions selectively quenched the fluorescence emission of Collagen-CuNCs (λ_em = 480 nm), among other tested metal ions. The fluorescence quenching mechanism was investigated using Stern-Volmer analysis and time-resolved fluorescence. With a nanomolar detection limit of 0.14 nM, the developed nanoprobe Collagen-CuNCs was employed to quantify Fe³⁺ ions in spiked blood serum.

A sustainable and highly sensitive spectrofluorimetric method was developed for the determination of ceftobiprole medocaril, a fifth-generation cephalosporin, in pharmaceutical dosage form and rat plasma samples. This approach utilizes carbon quantum dots functionalized through ion-pair formation with ceftobiprole and tetraphenylborate, creating a selective fluorescent probe. Quantification is based on a measurable decrease in fluorescence intensity at 450 nm following excitation at 365 nm, resulting from the interaction between the drug and the probe. Method parameters were systematically optimized and validated according to ICH guidelines, demonstrating excellent linearity (0.25–2.00 μg/mL), sensitivity (LOD = 0.07 μg/mL), and precision. The method was successfully applied to pharmacokinetic analysis in Wistar rats following a single 50-mg/kg intravenous infusion over 5 min. Pharmacokinetic parameters including C_max (45 μg/mL), T_max (0.25 h), half-life (3.17 h), and systemic clearance (0.45 L/h/kg) were obtained using non-compartmental analysis. Greenness evaluation using AGREE and GAPI tools confirmed the method's minimal environmental impact. The results affirm the method's applicability for routine quality control, therapeutic monitoring, and preclinical pharmacokinetic studies.

Acid phosphatase (ACP) serves as a critical biomarker for disease diagnosis, yet conventional detection methods face limitations in cost and complexity. Copper nanoclusters (CuNCs), leveraging Earth-abundance, low expense, and noble metal-like catalytic properties, offer an ideal nanozyme platform. This study harnesses the intrinsic peroxidase mimicking activity of CuNCs to construct a visual colorimetric sensor for ACP detection. CuNCs oxidize the substrate 3,3′,5,5′-tetramethylbenzidine (TMB) to generate a blue chromogen (λmax = 654 nm). ACP introduction triggers reduction of this chromogen, diminishing both color intensity and absorbance. The optimized sensor achieves a linear detection range of 0–6 U/L with a detection limit of 0.027 U/L, demonstrating high sensitivity and specificity. This CuNCs-based platform provides a rapid, low-cost, and operationally simple approach for ACP quantification, highlighting significant potential for clinical diagnostics.

A facile “turn-off” fluorescence sensing approach based on nitrogen and sulfur codoped carbon dots intercalated into graphitic carbon nitride (N, S-CDs@gC₃N₄) has been developed for the selective and sensitive detection of mercury ions (Hg²⁺). The sensor offers the synergistic interaction between N, S-CDs and gC₃N₄, where nitrogen and sulfur doping not only enhances fluorescence properties but also promotes strong Hg-S and Hg-N binding affinity. Upon interaction with Hg²⁺ the fluorescence of the N, S-CDs@gC₃N₄ composite is significantly quenched via static quenching mechanism (excitation/emission at 370/425 nm). The sensor shows a linear response to Hg²⁺ in the range of 1.0–7.2 μM (R² = 0.99) with a limit of detection of 0.421 μM. The method was successfully applied to detect Hg²⁺ in spiked tap and canal water samples at concentrations of 1.01, 2.84, and 4.47 µM, yielding recoveries of 98.89%–99.21% (RSD: 0.74%–2.26%) for tap water and 96.76%–98.03% (RSD: 0.61%–1.59%) for canal water. These results demonstrate the potential of N, S-CDs@gC₃N₄ for real-time application of Hg²⁺.

In this study, orange-red emitting Eu³⁺-doped Bi₇Ti₄NbO₂₁ (bismuth titanium niobate) (BTN) phosphors were successfully synthesized via the conventional high-temperature solid-state reaction (SSR) method. X-ray diffraction (XRD) confirmed phase purity, with diffraction peaks closely matching the JCPDS Card No. 00-031-0202 for both undoped and Eu³⁺-doped samples. Scanning electron microscopy (SEM) revealed irregular, micrometer-sized particles with mild agglomeration, suitable for photonic applications. Fourier-transform infrared (FT-IR) spectroscopy identified key vibrational modes within the BTN matrix, while the band gap was estimated using Tauc's method from diffuse reflectance spectra (DRS). DRS also indicated electronic transitions attributed to Eu³⁺ 4f orbitals. Photoluminescence (PL) measurements under 366-nm excitation displayed strong orange-red emission, with CIE coordinates at (0.6109, 0.3885). PL decay curves followed a bi-exponential trend at 595 nm emission, and increasing Eu³⁺ concentration led to reduced lifetimes (τ) due to energy migration among ions. Temperature-dependent PL (TDPL) analysis showed a peak relative sensitivity of ~0.71% K⁻¹ at 298 K, highlighting potential for optical temperature sensing. The combined structural, optical, and thermal characteristics underscore the suitability of Eu³⁺-doped BTN phosphors for advanced solid-state lighting, particularly in white LED and thermal sensing applications.

A novel fluorescent sensor ferrocenyl salicylaldehyde Schiff base derivative SF-Fc was designed, synthesized, and characterized by nuclear magnetic resonance (NMR), high-resolution mass spectrometry (HRMS), and SC-XRD spectroscopic analyses. The sensor was highly selective to trivalent ions Al³⁺, Cr³⁺, and Fe³⁺ over other monovalent or divalent ions and showed fluorescence enhancement towards trivalent metal ions (Al³⁺, Cr³⁺, Fe³⁺) in acetonitrile (pH 6). Detection limits of probe SF-Fc for Al³⁺, Cr³⁺, and Fe³⁺ were 1.2 × 10⁻⁷ mol/L, 2.4 × 10⁻⁷ mol/L, and 4.9 × 10⁻⁷ mol/L, respectively. In addition, the sensor exhibited an obvious color change in the presence of Cu²⁺ in acetonitrile solution, indicating a direct colorimetric naked-eye detection of Cu²⁺ without requiring instrumental assistance. Moreover, the probe SF-Fc successfully detected trivalent metal ions in actual water samples, with satisfactory recovery rates (88.7%–108.9%) and relative standard deviation (RSD) values (0.34%–2.91%).