Journal of Fluorescence最新文献

Methanol has become a very important part of many industries, ranging from chemical production and pharmaceuticals to automotive and electronics manufacturing as a result of which methanol usage has spiked in recent years. But this exponential increase asks for precise detection methods as methanol has not only detrimental effects on environment but it is very dangerous to human health even if consumed in a minute amount .This paper will explore the unique physical and chemical properties of methanol which can be exploited to make it a target for different mechanisms such as H-Bonding, induced self-assembly, Internal Charge Transfer (ICT), Aggregation-induced emission (AIE), conformational flexibility, keto-enol tautomerization, adsorption etc. by various small molecule and nano-particles. Informative studies on small molecules involves functionalized pentacenequinone derivatives, luminogens, ligands and fluorescent probes which can be used to detect methanol by change in color or intensity which can be easily detected in real time and is portable. On the other hand, nanoparticle-based probes reveal the use of materials like chitosan/zinc, sulfide composites, Quantum Dots (QDs) hybrids, graphene polyoxides, Ag-LaFeO₃ etc. which provides with selective and sensitive methanol optical and conductometric sensing. This paper acknowledges the contributions of various studies and researchers who contributed to advancing the field of methanol sensing, providing a foundation for future developments.

We aim to develop an amplified luminescence proximity homogeneous assay (AlphaLISA) for quantification of trypsinogen-2 levels in human serum for the diagnosis of acute pancreatitis. Based on new amplified luminescence proximity homogeneity assay (AlphaLISA) method, carboxyl-modified donor and acceptor beads were coupled to capture and detection antibodies. A double antibody sandwich immunoassay was used to detect the concentration of trypsinogen-2 in serum. The method had good linearity (> 0.998). The intra - analysis precision was between 1.54% and 2.20% (< 10%), the inter-analysis precision was between 3.17% and 6.94% (< 15%), and the recovery was between 96.23% and 103.45%. The cross-reactivity of carbohydrate antigen 242 (CA242) and T-cell immunoglobulin mucin-3 (Tim-3) were 0.09% and 0.93%, respectively. The detection time only needed 15 min. The results of trypsinogen-2-AlphaLISA and time-resolved fluorescence immunoassay were consistent (ρ = 0.9019). In addition, serum trypsinogen-2 concentration in patients with acute pancreatitis [239.23 (17.83-807.58) ng/mL] was significantly higher than that in healthy controls [20.54 (12.10-39.73) ng/mL]. When the cut-off value was 35.38ng/mL, the sensitivity and specificity were 91.8% and 96.67%, and the positive detection rate was 91.80%. We have successfully established a trypsinogen-2-AlphaLISA method, which can promote the timely diagnosis of acute pancreatitis.

In this study, carbon dots (CDs) were synthesized from Peltophorum pterocarpum flowers as the precursor material using the hydrothermal method. The fluorescence emission spectra of the resulting Peltophorum pterocarpum CDs (PP-CDs) exhibited excitation-independent behavior, showing the fluorescence emission peak at 410 nm when excited at 330 nm. This method is simple, rapid and well consistent with the green chemistry and sustainable analytical method development. The as-synthesized PP-CDs acted as a promising fluorescent probe for detecting carbendazim (CBZ) via aggregation-induced emission mechanism, showing a linear response to CBZ concentrations ranging from 1 to 30 μM, with a detection limit of 5.41 nM. This method was successfully applied to quantify CBZ in food samples, achieving excellent recoveries of 99% with a relative standard deviation (RSD) of less than 2%.

Understanding the development and performance of UV photodetectors is crucial, given their extensive applications in both military and civilian sectors. The evolution of self-powered photodetectors, especially those based on heterojunction nanostructures, has demonstrated significant potential for enhancing both device efficiency and functionality. By exploring the effects of material composition and structural design, can optimize these devices for improved photoelectric response and energy efficiency. In this study, we prepared the CuO/ZnO NRs heterojunction photodetector on an ITO substrate to enhance photoelectric response of UV detectors. The fabrication process utilized the hydrothermal method and the spin coating technique. The effect of CuO concentration on the optical response of the photodetector under UV radiation at wavelengths of 405 nm and 385 nm was investigated. The samples were characterized using FESSEM, XRD, EDX, and UV-Vis spectra. The device is further distinguished by its standard I-V curves and photocurrent-time curves, which demonstrate the device's behavior under various light conditions. The prepared thin films are polycrystalline, with CuO layers displaying monoclinic phases and ZnO layers exhibiting a hexagonal wurtzite phase. All samples have the potential to exhibit photovoltaic properties and self-powered capabilities. Furthermore, the I-V curve confirms that the photocurrent mechanism of these junctions adheres to the recombination standard, in addition to demonstrating correction behavior. A sample with a CuO concentration of 0.1 M shows the highest photosensitivity, reaching 340,700%, and a photocurrent gain (Iph/Idark) of 3,408 when exposed to light irradiation at 405 nm. Additionally, it exhibits a rapid response time of 0.8 s.

ZnO nanoparticles (NPs) were prepared and characterized by different analytical methods and then they were used to decorate with N, N´-bis(salicylidene)ethylenediamine (salen) in order to perform as receptor for the metal ions in an aqueous medium. The results show that ZnO-salen selectively detects Al³⁺ ions in aqueous medium since the intensity of fluorescence has been enhanced significantly. However, the presence of K⁺ in the medium further intensified the fluorescence emission for the [ZnO-salen-Al³⁺] system. The above system has been applied to recognize Al³⁺ and K⁺ in cells by developing the cell images, for which, the fluorescence image is brightened if a human glioblastoma U251 cell contains [ZnO-salen-Al³⁺] + K⁺ ions, consisting of the fluorescence titration. The binding global constant for Al³⁺ and the subsequent recognition of K⁺ by ZnO-salen resulted in β₂(Al³⁺) = 6.61 × 10³ and β₂(K⁺) = 3.71 × 10³ with a detection limit of 36.51 µM for Al³⁺ and 17.39 µM for K⁺. In the cell toxicity analysis, the cell viability was over 85% for the ZnO-salen even in the concentration as high as 100 mM.

In this study, an NH₂-Cu-MOF was synthesized using the one-pot method and employed as a fluorescence probe for doxorubicin (DOX) detection. The synthesized NH₂-Cu-MOF exhibited remarkable fluorescence recognition capabilities for detecting DOX. Within the concentration range of 1-100 µmol/L, a linear relationship was observed between the fluorescence intensity of the NH₂-Cu-MOF and the DOX concentration. Furthermore, the synthesized NH₂-Cu-MOF was effectively utilized for highly selective fluorescence quenching recognition and quantitative detection of DOX in the presence of multiple metal ions and other antibiotics. Despite interference from multiple metal ions and antibiotics, DOX was identified and quantified by highly selective fluorescence quenching with a detection limit of 2.1654 µmol/L. These findings underscore the potential of NH₂-Cu-MOF as a class of "on-off" fluorescent probes for the rapid detection of DOX.

The biologically active and thermally stable bivalent Co(II), Ni(II), Cu(II), and Zn(II) complexes (C1, C2, C3, and C4) of novel Schiff base ligand [(5-trifluoromethyl-2-methoxyphenylamino)methyl)-4,6-diiodophenol (L)] have been synthesized. The structural analysis of these complexes have been carried out by elemental analysis, ¹H-NMR, FTIR, ESI mass, UV-visible, ESR, TGA techniques and magnetic measurements. The obtained results were confirmed as square planar geometry for Ni(II) and Cu(II) complexes, whereas octahedral geometry for Co(II) and Zn(II) complexes. The geometry optimized structures were developed by employing CHEM 3D software. The DNA binding interaction studies such as UV-vis absorption, viscosity, and fluorescence studies have been confirmed that the mode of binding of complexes with DNA is an intercalative binding. The DNA cleavage studies revealed that all the complexes are found to be potent to cleave the DNA into Form I & II. The in-vitro pathological studies of all the complexes against various microbial strains (Gram + and Gram -), revealed that Cu(II) complexes are more potent compared to other complexes and Schiff base. The anti diabetic activity studies revealed that the Cu(II) complex exhibited slightly higher activity than Co(II), Ni(II), and Zn(II) complexes. The results of antioxidant activity by DPPH method, suggested that the Cu(II) complex has higher activity and comparable with the standard compounds.

Co-doping strategy is done if the emission from the activator is relatively low with existing excitation energy. Thus, to enrich the emission from an activator, the sensitizer like Bi³⁺ is co-doped onto the host and this intermediator transfers its emission energy to the activator. Prior to the study, no investigations had been conducted, marking the foundational exploration of the sensitizer effect within the rare earth-doped SrCeO₃ matrix aimed at enhancing luminescence properties. The current study focuses on the innovation of single-phase robust white phosphors, SrCeO₃: 2wt% Sm³⁺: xBi³⁺ (x = 0 wt%, 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%) to coat near UV LED chips for high CRI wLED applications. The novel perovskites were synthesized using a low-temperature fuel excess gel combustion method, utilizing citric acid as the fuel and ammonium nitrate as an extra oxidizer. Upon co-doping SrCeO₃: 2wt% Sm³⁺ with bismuth, the impact of changing sensitizer concentration on both the development of crystalline phases, morphology, elemental composition, band gap energy, and the luminescent properties of ceramic powders were explored through X-ray diffraction, FE-SEM, Energy dispersive spectra, UV-visible absorption spectra, and photoluminescence characterization methods. The experimental results revealed the orthorhombic single-phase formation of SrCeO₃: 2wt% Sm³⁺: xBi³⁺perovskites yielding high crystallinity and luminescence maximum at critical sensitizer concentration 1 wt% Bi³⁺. Also, the bright white light emission of all the perovskites was confirmed using the CIE color diagram. Thus, nano-perovskite SrCe_0.97Sm_0.02O₃: 1wt% Bi³⁺ acts as an inevitable direct phosphor coating the near UV chip in LEDs, which can be a great revolution in energy savings applications.

A newly green method for the sensitive quantification of cloperastine, a cough suppressant, in spiked human plasma and its pharmaceutical formulation was designed for the first time. The established method depends on the enhancement of the weak fluorescence of cloperastine using 50 mM sulfuric acid to impair the photoinduced electron transfer produced from the nitrogen atom of piperidine moiety in cloperastine. This full protonation in an acid medium leads to an enhancement in the fluorescence of cloperastine, permitting its linear determination from 0.2 to 5.0 µg/mL with LOD and LOQ of 0.04 and 0.13 µg/mL, respectively. Moreover, the studied drug was estimated in its pharmaceutical market formulations as well as spiked human plasma. Furthermore, the greenness of the described method was evaluated.

In this work, a series of dibenzimidazole derivatives 1-4, act as highly reversible colorimetric and fluorescent pH chemosensor, were designed and synthesized. Excellent reversible pH response of these sensors could be found by a specific pH change through obvious fluorescent color changes. The response is not affected by common cations (including Al³⁺, Cu²⁺, Ca²⁺, Cd²⁺, Co²⁺, Cr³⁺, Mg²⁺, Na⁺, K⁺, Ni²⁺, Pb²⁺ and Zn²⁺) and anions (including F^-, Cl^-, Br^-, I^-, ClO₄^-, H₂PO₄^-, HSO₄^-, HCO₃^- and CH₃COO^-). Notably, these sensors can be reused more than 10 times without losing functionality. Unlike previous reports, the distinct properties of 1-4 are attributed to the varied link groups. Based on comprehensive experimental data and mechanistic analyses, it is concluded that sensors 1-4 are promising candidates for use as highly reversible "on-off-on" fluorescence switches under precise pH control.