Luminescence最新文献

This study focuses on enhancing the performance of photodetector through the utilization of inorganic perovskite material. It emphasizes that the unique properties of perovskite materials contribute to the superior performance of the photodetector. The focus is on the design and enhancement of CsSnI₃-based photodetector having graphene oxide (GO) and PCBM as charge transport layer, analysing their potential for improved operation. The design process involves a series of optimizations to the device layers, particularly the absorber layer's thickness and defects, which is critical for enhanced efficiency. The designed photodetector exhibits a better responsivity and detectivity in red and near infrared region and maximum responsivity of 0.68 A/W and detectivity of 9 × 10¹² Jones. The SCAPS-1D tool is employed to facilitate the design analysis, enabling the fine-tuning of the device parameters. The findings highlight the effectiveness of perovskite materials in boosting photodetector performance.

Crystal Violet (CV) is a vibrant and harmful dye known for its toxicity to aquatic life and potential carcinogenic effects on humans. This study explores the removal of CV through photocatalysis driven by visible light, as well as examining the antibacterial and antibiofilm characteristics of zinc oxide nanoparticles (ZnO NPs) synthesized from the aerial roots of Ficus benghalensis. Various characterization techniques were employed to confirm the optical properties, crystal lattices, and morphology of ZnO NPs. TEM images showed that the ZnO NPs had a spherical shape, with an average size of 40 to 80 nm. The photocatalytic analysis revealed that the synthesized ZnO NPs exhibited substantial activity under visible light, effectively degrading 90.6% of CV in an aqueous solution. The antibacterial activity of synthesized ZnO NPs was evaluated against clinically relevant bacterial strains such as Pseudomonas aeruginosa and Bacillus subtilis, revealing notable zones of inhibition. Moreover, the ZnO NPs exhibited antibiofilm activity of 96.8 ± 0.5% and 98.3 ± 0.3% against P. aeruginosa and Staphylococcus aureus, respectively. In conclusion, this study demonstrated the potential of the synthesized ZnO NPs as a sustainable solution for wastewater treatment and antibacterial applications.

In the present study, a norfloxacin (NFX) fluorescent probe was tailored for the spectrofluorometric measurement of cefepime (CFP). The proposed approach measured the quenching effect of CFP on the fluorescence intensity of NFX in acetate buffer solution. The obtained results show that CFP strongly quenches the fluorescence of NFX in a static mechanism. Under the optimal conditions, plotting the fluorescence quenching values (∆F) against CFP concentrations resulted in two ranges varying from 0.8 to 28 μg/mL (r² = 0.9979) and from 40 to 92 μg/mL (r² = 0.9929). Furthermore, the limits of quantification and detection were 2.0526 and 0.6773 μg/mL, respectively. In terms of intra- and inter-day recorded precisions (n = 5), the % RSD ranged between 0.31% and 0.6% and 0.55% and 1.02%, respectively. Additionally, practicality/applicability and the green feature of the new method were considered by BAGI and AGREE automated approaches. The new spectrofluorometric approach was positively applied for the quantification of CFP in injection powder and spiked biological fluids, including spiked human urine and plasma samples. According to previously published fluorescence methods, the present method is considered the first fluorescence one for the assay of CFP in human biological fluids with accurate and precise results.

Two versatile yet simple methods, colorimetric and spectrofluorimetric, were utilized for the quantitation of nonchromophore neomycin using silver nanoparticles modified with fluorescein. Fluorescein was excited at 485 nm (emission at 515 nm); when it is deposited on the surface of silver nanoparticles, its fluorescence intensity at 515 nm is quenched. Neomycin restores the fluorescence level at 515 nm by displacing fluorescein from nanoparticle binding sites. When neomycin reacts with silver nanoparticles modified with fluorescein, it causes reduction of silver nanoparticles' plasmon resonance surface band at 395 nm and changes of the solution's color from yellow to pale pink. For the spectrofluorimetric and colorimetric techniques, the calibration graphs with a linearity range of 5–45 ng/mL and 0.5–10 μg/mL, respectively. The suggested techniques were used to determine neomycin in neomycin tablets, yielding mean recovery of 99.696 ± 0.764 and 99.925 ± 1.515 for the spectrofluorimetric and colorimetric methods, respectively. The established techniques were validated according to the ICH guidelines. Analytical greenness calculator (AGREE) along with greenness tool for sample preparation (AGREEprep) was used to evaluate how environmentally friendly the sample preparation and analytical process were. In addition, the suggested approaches' practicality is assessed using the Blue Applicability Grade Index (BAGI).

Bioluminescence inhibition (BLI) measurements in bioluminescent bacteria (BB) is perceived as a potential qualitative and quantitative indicator of hazardous materials. Acute but minor fluctuations in osmolarity and pH do not affect the living systems significantly. However, significant BLI is observed from marine BB due to acute osmolarity or pH changes that may affect the bioassay sensitivity. Often, real samples have low pH and osmolarity, interfering with the hazard assessment based on the principles of BLI. This anomaly in BLI measurements may lead to false positives. Therefore, modifications in existing analytical methods to overcome such practical constraints are envisaged. In the present research, a marine BB was utilized to study the luminescence reversal effect when exposed to stressful environments such as hypotonic (deionized water), acidic (50 μM to 50 mM HCl), and 0.1–100 ppm of Hg(II) for 0–30 min. Postincubation, the calcium alginate immobilized bioluminescent bacteria (biophotonic beads) were transferred to Boss media to observe any luminescence enhancement. The results showed that osmotic shock and low-strength acidic environments (50 μM to 0.5 mM HCl) at specified incubation times were not detrimental to the biophonic beads regarding luminescence response.

Mercury ions (Hg²⁺) seriously harm the central nervous system of humans, leading to brain damage and even heart failure and death. Therefore, effective detection of Hg²⁺ in water quality has become an urgent research field. It is very important to develop economically efficient fluorescent sensors to achieve rapid and sensitive detection of Hg²⁺. Therefore, the high fluorescence quantum yield fluorescent carbon dots (CDs) with amide group were prepared. The process of preparing CDs was regulated by multiple key factors (carbon source, proportion, time), and the CDs with the best fluorescence performance were selected. It was comprehensively characterized, including fluorescence performance, surface structure, phase, and morphological characteristics. The amide group endows CDs with the ability to act as both donors and acceptors for hydrogen bonding, forming complexes with metal ions, thus making them suitable for the detection of Hg²⁺. It is worth noting that CDs can quickly detect Hg²⁺ within 1 min, and there is a good linear relationship within the ranges of 0.001–200 μM and 200–500 μM. The detection limit of UC-CDs is 8.2 nM. This study provides a fluorescent sensor with fast reaction, excellent sensitivity, and selectivity for the efficient detection of Hg²⁺ in water.

Herein, a novel spectrofluorometric sensor is proposed for the sensitive analysis of two nonfluorescent mucolytic drugs, namely, acetylcysteine (ACT) and carbocisteine (CST), utilizing the newly synthesized 2-[(2-hydroxyethyl)-(2,8,10-trimethylpyrido[2′,3′:3,4]pyrazolo[1,5-a]pyrimidin-4-yl)-amino]-ethanol as a fluorescence probe (Flu. Probe). This fluorophore exhibits fluorescence emission at 445 nm upon excitation at 275 nm. The addition of increasing concentrations of each drug resulted in quantitative quenching of the Flu. Probe's fluorescence. Investigation into the quenching mechanism revealed that static quenching is the primary contributing factor for both drugs. The spectroscopic characteristics of the Flu. Probe in the presence of ACT and CST were analyzed using DFT and TD-B3LYP calculations, revealing typical π → π* transitions, attributed to stable hydrogen-bonding structures. The developed method was validated in accordance with ICH Q2(R1) guidelines. Linear responses for ACT and CST were observed over concentration ranges 0.125–2.25 and 0.125–3.0 μg/mL, respectively, with detection limits (LODs) 31.97 and 37.14 ng/mL. The proposed spectrofluorometric platform was successfully applied to the analysis of ACT and CST in pharmaceutical dosage forms and spiked urine, within concentration ranges 0.25–2.25 and 0.25–2.50 μg/mL and LODs = 80.21 and 71.48 ng/mL, respectively. Finally, the greenness of the proposed protocol was evaluated employing GAPI, hexagon, and AGREE approaches.

In this paper, a series of BaSrCaWO₆:x%Mn⁴⁺, y%La³⁺ (x = 0.1, 0.5, 0.6, 1.5; y = 0, 5, 10, 15, 20) red-emitting phosphors were synthesized by the high-temperature solid-state method. The structure and optical properties of the samples were systematically studied by the characterizations of x-ray diffraction (XRD), scanning electron microscope (SEM), UV–Vis spectra, photoluminescence (PL) spectra, photoluminescence excitation (PLE) spectra, and quantum efficiency (QE). It was found that the addition of La³⁺ ions plays significant roles on the luminous performance of phosphors as compared with the nonluminous BaSrCaWO₆:Mn (BSCW:Mn), which can be attributed to the Mn²⁺ → Mn⁴⁺ oxidation process induced by La³⁺ doping. The BSCW:0.5%Mn, 15%La³⁺ phosphor exhibited a strong emission peak at 685 nm with a CIE chromaticity coordinate at (0.720, 0.279), which is suitable for application in indoor plant cultivations. The BSCW:0.5%Mn, 15%La³⁺ phosphor exhibited an IQE of 47.8% and a high absorption efficiency of 72.8% with the EQE of 34.8%. Besides, the phosphor also showed the thermal stability with the emission intensity at 423 K being 48% of the emission intensity at 298 K. These results indicate that the synthesized BSCW:0.5%Mn, 15%La³⁺ phosphor could be a potential phosphor to be applied in plant growth LEDs.

Currently, the development of red Mn⁴⁺-activated fluoride luminescent materials attracts a lot of attention in optical thermometry sensors, solid lighting, display, and plant growth areas. Nevertheless, the thermal stability of Mn⁴⁺-activated fluoride luminescent materials is still a crucial issue. Herein, a new red Rb₂NaVF₆:Mn⁴⁺ luminescent material with outstanding thermal stability was successfully synthesized through the facial coprecipitation method. Mn⁴⁺ ions prefer to occupy VF₆ octahedra based on the accurate Rietveld refinement results. Accordingly, the as-prepared Rb₂NaVF₆:Mn⁴⁺ exhibits a broad absorption region from 300 to 500 nm with a maximum of 468 nm, matching well with the near-ultraviolet and blue InGaN chip. Upon 468 nm excitation, Rb₂NaVF₆:Mn⁴⁺ can emit narrow-band red light at 632 nm. Notably, Rb₂NaVF₆:Mn⁴⁺ shows superior antithermal quenching properties, of which the integrated intensities at 175°C can realize as high as 140% than that at 25°C. Owing to the diverse thermal quenching behavior between anti-Stokes and Stokes emission, Rb₂NaVF₆:Mn⁴⁺ displays promising candidates in optical thermometry sensors with a relative sensitivity S_r of 0.49%. This study offers new insight into developing antithermal quenching red Mn⁴⁺-activated fluoride luminescent materials.

Herein, highly fluorescent sulfur and nitrogen co-doped carbon dots (N, S-CDs) had been employed as a fluorescent probe to analyze Cu²⁺ in drinking water. The biogenic creatinine is known to form a stable complex with Cu²⁺; hence, it was rationally selected as a bioinspired nitrogen substrate for the first time to enhance N, S-CDs selectivity towards Cu²⁺. Moreover, the literature was surveyed to guide the selection of sulfur and carbon sources to optimize N, S-CDs quantum yield (QY), so thiourea and disodium edetate are co-carbonized with biogenic creatinine at 270°C for 40 min and characterized using different techniques. The resulting N, S-CDs have a homogeneous particle size distribution and high QY (60.5% ± 2.09%, n = 5). The produced N, S-CDs fluorescence intensity (FI) had been quantitatively quenched by Cu²⁺, achieving a detection limit reached of 0.07 μM. The developed environmentally friendly and sustainable platform, according to the results of three widely greenness assessment tools and the innovative RGB 12 model, had been successfully employed to detect Cu²⁺ in drinking water with excellent recovery. Finally, as this sensing platform is rapid and selective, it can be successfully employed to determine the Cu²⁺ in real-life applications.