Journal of Fluorescence最新文献

The review explores the pivotal role of cellulose in enhancing the sensing capabilities of fluorescent chemo-sensors, particularly carbon dots (CDs) and delineates cellulose's multifaceted contributions as both a precursor and stabilizing matrix, highlighting its structural adaptability across varied forms-hydrogels, aerogels, films-to bolster the stability, sensitivity, and selectivity of these sensors. Cellulose's structural versatility enables advanced functionalization, fostering a robust platform that amplifies the stability and functional efficiency of CDs across diverse sensing paradigms. The investigation encompasses utilization of cellulose as precursor for CDs, cellulose nanocrystals and matrix for the integration of CDs, elucidating their collective impact on advancing fluorescence-based detection technologies.

This study, we employed computer-aided design to develop 27 peptide aptamers, and initially screened 11 candidates with binding energies less than - 6.0 kcal/mol. Subsequently, three peptide aptamers with strong specificity were selected using a direct time-resolved fluorescence immunoassay (TRFIA). Peptide aptamer B3, in combination with monoclonal antibody R001, was used to construct a TRFIA-based sandwich assay system. The performance of this system was evaluated concerning sensitivity, specificity, and reproducibility, and was further tested using 20 simulated pharyngeal swab samples. The dominant peptide aptamer, B3(RGQGVPI), was identified as the most promising candidate. This peptide demonstrated high specificity for the SARS-CoV-2 nucleocapsid (N) protein, with the lowest detectable concentration of 203.78 pg/mL. Importantly, the peptide had no cross-reactions with other potential interferents, including RSV, Flu A, and MP, confirming its specificity. The assay also exhibited good reproducibility, with coefficients of variation of 11.33% and 8.00% at different concentrations in pharyngeal swab samples. Additionally, the LOB and LOD in clinical samples were 31.59 pg/mL and 243.70 pg/mL and the correlation coefficient R² was 0.9784, which indicated that the method had good resistance to clinical interference. In this study, we successfully developed a sandwich TRFIA method based on the peptide aptamer B3-R001, which can be used to quantitatively measure the SARS-CoV-2 N protein level in pharyngeal swabs. Compared to antibodies, peptide aptamers are easily synthesized, inexpensive, and show great potential for clinical applications. This method provides a novel approach for rapidly detecting viral pathogens, contributing to the advancement of diagnostic tools.

The photophysical properties of an anthraquinone based dye, Solvent Green 3 (SG3) were investigated in chloroform solution and stearic acid supported Langmuir-Blodgett films (SG-LB) by steady state and time-resolved spectroscopic techniques. Both steady state and time-resolved studies were performed for SG3 in chloroform solution (1 µM) whereas only steady-state measurements were performed for the SG-LB films. The studies revealed that the photodynamics of SG3 are guided by deexcitation of energetically separated conformers and aggregates of SG3, namely the closed form (CF) and open form (OF) in solution. However, in SG-LB, the OF dominates the photophysical properties. The current report sheds light on the effect of conformational confinement on the photophysical properties of organic dye molecules, thereby enabling better understanding of photo behaviour of small organic molecules.

A multi-function fluorescent probe HT was synthesized from 2,4-dihydroxybenzaldehyde and 6-methoxy-2-naphthaldehyde. HT demonstrated a remarkable turn on response to detect Zn²⁺ in ethanol solution with strong anti-interference ability. Additionally, HT exhibited exceptional proficiency in discerning minute traces of water present in conventional organic solvents. The detection limit for Zn²⁺ was 1.88 × 10^- 7 mol·L^- 1, with a coordination ratio of 2:1 between HT and Zn²⁺. Furthermore, the detection limits of HT for water in various solvents such as EtOH, DMSO, DMF, CH₃CN, THF, 1,4- Dioxane were 0.0089%, 0.0211%, 0.0364%, 0.0472%, 0.0161%, 0.0116% (V/V), respectively. Moreover, HT demonstrated its practical application potential by accurately determining the alcohol content in different Chinese Baijiu samples.

Fluorescent sensing technologies have emerged as powerful tools in analytical science, offering exceptional sensitivity and selectivity for detecting a wide range of analytes. Among the advanced materials driving these technologies, quantum dots (QDs) and metal nanoparticles (MNPs) stand out due to their unique optical and electronic properties. When combined, these materials exhibit synergistic interactions those significantly enhance the fluorescence signals, enable efficient quenching, and offer tunable optical properties. This review explores the various protocols involved in the development, characterization, and performance evaluation of metal-QD composites; typically, metal-enhanced fluorescence (MEF) and Förster resonance energy transfer (FRET). The applications of the materials in the domain of biomedical diagnostics, environmental monitoring, and biosensing have been highlighted. The review also discusses the current challenges and future scope in the field of metal-QD-based fluorescent sensors and their possible transformative impact on next-generation sensing technologies.

In this study, we designed and synthesized a novel thio-purine analog, compound 1, which exhibits significant fluorescence properties due to its extended conjugated system, heteroatom incorporation (O, S, N), and rigid three-dimensional molecular framework, enabling its use as a fluorescence probe for real-time drug tracking and release monitoring. To enhance the solubility, biocompatibility, and therapeutic efficacy of compound 1, we synthesized a copper(II)-based coordination polymer (CP1) via hydrothermal methods, featuring a three-dimensional framework formed by 1,4-ttb and auxiliary ligand 4,4'-bpdc, as confirmed by comprehensive characterization techniques. Leveraging the synergistic therapeutic effects of compound 1 and fenelidone, we developed a composite drug delivery system, mPEG-PSU@CP1@1@fenelidone, which combines an amphiphilic mPEG-PSU shell with a CP1 core co-encapsulating both drugs. Notably, the fluorescence properties of compound 1 allow for real-time monitoring of drug release, as its fluorescence is quenched when encapsulated in CP1 and restored upon release. This system optimizes controlled drug release while enhancing the synergistic effects of compound 1 and fenelidone in reducing inflammation and renal fibrosis, as demonstrated in diabetic nephropathy (DN) model mice. Overall, the composite system integrates real-time fluorescence monitoring with improved therapeutic efficacy, offering a promising strategy for diabetic nephropathy treatment.

This study introduces the synthesis of amino acid-based nitrogen-doped carbon dots (N-L-Ser-CDs) from L-serine (L-Ser) and urea through a straightforward and economical one-step solid-phase pyrolysis process. The incorporation of nitrogen into the carbon dots resulted in a remarkable 27.6-fold increase in fluorescence intensity, featuring a peak emission at 405 nm when excited at 330 nm and a significant fluorescence quantum yield of 22.5%. These N-L-Ser-CDs displayed a specific binding affinity for Cu²⁺, leading to a pronounced fluorescence quenching effect. However, upon interaction with glutathione (GSH), the fluorescence of the N-L-Ser-CDs + Cu²⁺ complex was selectively restored. This restoration was attributed to the displacement of Cu²⁺ from the surface of the N-L-Ser-CDs due to the strong interaction between GSH and Cu²⁺. The mechanism underlying this fluorescence quenching was elucidated as an electron transfer process from the excited state of the N-L-Ser-CDs to Cu²⁺. Additionally, the sensor developed in this study exhibited a linear detection range of 0-90 µM for Cu²⁺ with a detection limit of 3 µM, and a linear detection range of 0-120 µM with a detection limit of 3 µM for GSH. By integrating the detection capabilities for both Cu²⁺ and GSH, a successful "on-off-on" fluorescent probe was developed. Most importantly, this proposed method offers simplicity, affordability, and ease of use, while also showing potential for practical GSH detection in real urine samples.

Corrosion poses significant challenges in both industrial applications and everyday life, necessitating effective corrosion control strategies to mitigate costs and enhance safety. This research investigates the anti-corrosion potentials of purine derivatives-hypoxanthine (1), xanthine (2), theophylline (3), theobromine (4), uric acid (5), and isoguanine (6)-using density functional theory (DFT) and Monte Carlo simulations. Electronic properties, including energy gaps, HOMO and LUMO energies, molecular electrostatic potential (MEP) surfaces, and global reactivity descriptors, were computed at the B3LYP/6-311 + + G(d, p) theoretical level. Monte Carlo simulations were employed to evaluate the adsorption efficacy of these compounds on Fe(110) and Cu(111) surfaces. The findings reveal significant electron charge transfer from the molecules to the metal surfaces, with uric acid (5) and isoguanine (6) exhibiting the highest inhibition efficiencies. Adsorption energy calculations indicate that compounds 3 and 4 exhibit lower adsorption energies on Fe(110), while adsorption on Cu(111) surfaces demonstrated approximately 1.5 times lower absolute values. These results highlight the potential of purine derivatives, particularly compounds 5 and 6, as effective corrosion inhibitors for metal surfaces.

With the pressure for renewable energy resources and the enchantingly digitalized current lifestyle, the need for batteries will augment. Therefore, in this article, it has been evaluated the promising alternative alkali metals of sodium-ion and potassium-ion, batteries. The hypothesis of the hydrogen adsorption phenomenon was confirmed by density distributions of charge density differences (CDD), total density of state (TDOS), and electron localization function (ELF) for of Li[GeO-SiO], Na[GeO-SiO] or K[GeO-SiO] heterostructures that have revealed an efficient charge transfer owing to the internal electric field. Regardless of adsorption configurations of H₂ molecules, the region of charge density variation is mainly concentrated between the H₂ molecule and the layers of Li[GeO-SiO], Na[GeO-SiO] or K[GeO-SiO] heterostructures atoms. The maximum energy of TDOS for K[GeO-SiO] with several peaks around -0.35, -0.45, -0.6 and -0.75 a.u. with maximum density of state of ≈ 23 around -0.35 a.u. has been revealed. As the advantages of lithium, sodium or potassium over Si/Ge possess its higher electron and hole motion, allowing lithium, sodium or potassium instruments to operate at higher frequencies than Si/Ge instruments. K[GeO-SiO]-2H₂ and Na[GeO-SiO]-2H₂ heterostructures with band gap of 0.9230 and 0.8963 eV, respectively can be more efficient for hydrogen grabbing. The findings suggest that the proposed heterostructures offer appropriate band edge positions for saving energy in the batteries. Furthermore, the calculations have revealed that non-magnetic dopants can induce stable half-metallic ferromagnetic ground state in Li/Na/K. In particular, at the same levels of doping, the K/Na-doped [GeO-SiO] heterostructure framework exhibited the strongest H₂ binding.

Lead is a highly toxic poison for the human body. Lead poisoning is a fatal condition severely affecting the mental and physical development of children younger than 4-5 years. Among various chemo sensors, heterocyclic derivatives are widely used to chelate toxic metal ions, leading to changes in their optical, absorbance, and spectroscopic properties. In this study, coumarin heterocyclic hybrids C1-C6 were synthesized by reacting different classes of amine, pyrrole, and thiadiazoles with bromo acetyl coumarin at room temperature. The C1-C6 probes are studied for their metal binding ability in aqueous acetonitrile for Cu²⁺, Ni²⁺, Mn²⁺, Pb²⁺, and Zn²⁺ ions. All six probes showed significant binding with Pb²⁺ ions with good selectivity by UV-visible, NMR, and HPLC studies. The high binding constants and efficiency of probes between 0.00003-0.00006 range further point to their likely use in human biomatrix' s for Pb²⁺ detection.