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oe1(光电查) - 科学论文

38 条数据
?? 中文(中国)
  • Optical responses of BSA protein under re-entrant condensation in presence of trivalent ions

    摘要: Fluorescence behavior of globular protein like BSA is studied under the re-entrant condensation in the presence of trivalent salts like YCl3 and LaCl3. BSA shows a re-entrant behaviour in solution where a specific turbid phase is formed between the two critical concentrations of the trivalent salts. Optical behaviours of proteins are explored by UV-Vis, photoluminescence and time resolved photoluminescence (TRPL) spectroscopy, whereas hydrodynamic size is obtained from the dynamic light scattering (DLS) technique. BSA shows maximum emission intensity at ≈ 338 nm for an excitation at 278 nm, however, the value of the peak intensity of emission gradually increases with the increase in salt concentration and becomes maximum at the turbid phase but for higher salt concentration as the re-dissolution takes place the emission intensity again decreases. TRPL study suggests that the decay time of BSA under re-entrant condensation is correlated with the salt concentration, whereas DLS study shows that the hydrodynamic size gradually increases up to a certain salt concentration where turbid phase is formed and then again decreases for higher salt concentrations. The variation of emission intensity of BSA nearly follows the modification of diffusion coefficient or hydrodynamic size and the phase transition behaviours.

    关键词: UV-Vis spectroscopy,Bovine serum albumin,Tri-valent ions,Re-entrant condensation,Fluorescence spectroscopy

    更新于2025-09-23 15:23:52

  • Radioiodinated Portable Albumin Binder as a Versatile Agent for in vivo Imaging with Single-Photon Emission Computed Tomography

    摘要: In this study, radioiodinated 4-(p-iodophenyl)butyric acid ([131I]IBA) was synthesized and evaluated as a portable albumin-binder for potential applications in SPECT imaging of blood pool, tumor and lymph node with significantly improved pharmacokinetic properties. The [131I]IBA was prepared under the catalyst of Cu2O/1,10-phenanthroline. After that, the albumin-binding capability of [131I]IBA was tested in vitro, ex vivo and in vivo, respectively. [131I]IBA was obtained with very high radiolabeling yield (> 99%) and good radiochemical purity (> 98%) within 10 min. It binds to albumin effectively with high affinity (IC50= 46.5 μM) and has good stability. The results of biodistribution indicated that the [131I]IBA was mainly accumulated in blood with good retention (10.51±2.58%ID/g at 30 min p.i. and 4.63±0.17%ID/g at 4 h p.i.). In the SPECT imaging of mice models with [131I]IBA, blood pool, lymph node and tumors could be imaged clearly with high target-to-background ratio. Overall, the radioiodinated albumin binder of [131I]IBA with long blood half-life and excellent stability could be used to decorate diversified albumin-binding radioligands and developed as a versatile theranostic agent.

    关键词: SPECT,in vivo imaging,radioiodination,albumin binder,animal models

    更新于2025-09-23 15:23:52

  • Quantification of Glucose via in situ Growth of Cu2O/Ag Nanoparticles

    摘要: The monitoring of glucose levels in blood is extremely important for the effective control of diabetes. Nanomaterial-based approaches for the quantification of glucose typically require two steps: material preparation and the actual glucose measurement. Herein, we report a single-step method that combines these functions via the in situ growth of Cu2O/Ag nanoparticles (NPs). Mechanistically, we use glucose itself to reduce Cu2+ and Ag+ ions that are stabilized with 3-mercaptopropionic acid (3-MPA) and bovine serum albumin (BSA) under alkaline conditions to form Cu2O/Ag NPs and produce a color change in solution due to plasmonic resonance at 400 nm, which can be related back to the concentration of glucose. We study several factors in this reaction, including the molar ratios of the metal ions and 3-MPA, the reaction time, and the temperature to control the synthesis of the Cu2O/Ag NPs and thus their sensitivity toward glucose. Introducing BSA into the system is a key factor for the quantification of glucose in blood without pretreatment, improving the probe’s limit of detection and reducing the sample volumes to 1 μL. This colorimetric assay based on Cu2O/Ag NPs exhibits excellent sensitivity and specificity toward glucose, and a linear relationship with glucose concentrations ranging from 15 to 300 μM and a limit of detection of 9.2 μM. As proof of concept, we demonstrated that the Cu2O/Ag NP probes could successfully detect glucose in two representative blood samples by neglecting interferences from various common species, demonstrating the potential of this technique in point-of-care analysis.

    关键词: plasmonic resonance,3-mercaptopropionic acid,bovine serum albumin,silver nanoparticles,glucose quantification,Cu2O

    更新于2025-09-23 15:23:52

  • Squaraine dyes: interaction with bovine serum albumin to investigate supramolecular adducts with aggregation-induced emission (AIE) properties

    摘要: Bovine Serum Albumin (BSA)–squaraine supramolecular adducts with aggregation-induced emission (AIE) properties were prepared and characterized by spectroscopic methods. While squaraine dyes showed very low fluorescence quantum yield in water, a great enhancement in the fluorescence of the aggregated BSA adducts was achieved due to the abnormal aggregation-induced emission properties of squaraines. The adducts formation was studied from a kinetic point of view showing unexpected structure-properties relationships.

    关键词: squaraines,supramolecular adducts,Bovine Serum Albumin (BSA),kinetics,Aggregation-induced emission (AIE)

    更新于2025-09-23 15:22:29

  • Potassium triiodide-quenched gold nanocluster as a fluorescent turn-on probe for sensing cysteine/homocysteine in human serum

    摘要: A fluorescent sensing platform using KI3-quenched bovine serum albumin stabilized gold nanoclusters has been designed and used as a fluorescent probe for the turn-on detection of homocysteine/cysteine (Cys/Hcy). The fluorescence of gold nanoclusters was quenched by iodine. The fluorescence of quenched gold nanoclusters was effectively switched on by Cys/Hcy devoid of the interference of glutathione. The transmission electron microscopy image, X-ray photoelectron spectroscopy analysis, time-correlated single photon counting analysis, and dynamic light scattering data confirmed the aggregation-induced quenching of fluorescence of gold nanoclusters by iodine. The turn-on response of Cys/Hcy shows two linear ranges from 0.0057 to 5 μM and from 8 to 25 μM, with a limit of detection of 9 nM for cysteine and 12 nM for homocysteine. Real samples were analyzed to monitor Cys/Hcy added to human serum. The fluorescence turn-on response of the probe on a paper strip in the presence of Cys/Hcy was studied.

    关键词: Cysteine,Fluorescence turn on,Gold nanocluster,Bovine serum albumin,Iodine,Homocysteine

    更新于2025-09-23 15:22:29

  • Red emitting human serum albumin templated copper nanoclusters as effective candidates for highly specific biosensing of bilirubin

    摘要: In this paper, we report a new type of human serum albumin (HSA) stabilized red emissive copper nanoclusters (HSA?CuNCs) were prepared at room temperature and HSA?CuNCs were applied to identify the bilirubin in human urine and blood serum samples. The emission characteristics of synthesized HSA?CuNCs were pH responsive to that the intensity of emission enhanced quickly with varying the pH range from 12 to 6. Emission spectral signal of HSA?CuNCs was found as reduced well with the raise in the amounts of bilirubin attributed to strong binding attraction leads to the non-fluorescent complex formation of HSA?CuNCs with bilirubin. Due to the strong affinity between the nanoprobe and analyte, the red emissive HSA?CuNCs illustrates more specific for the detection bilirubin over the different potential interfering molecules. Two good linear relationships were distinguished the relative emission intensity of HSA?CuNCs versus bilirubin concentrations range from 1.25 × 10-6 to 7.50 × 10-6 M and 5.00 × 10-6 to 2.875 × 10-5 M with lowest limit of detection was determined as 35.00 × 10-9 M and 145.00 × 10-9 M (S/N = 3), respectively. Furthermore, this methodology was effectively used in the quantification of bilirubin in clinical (real) samples. In addition, this fluorometric method offers cost-effective, easy, highly specific and ultrasensitive optical platform for the determination of bilirubin.

    关键词: Red emittive,pH-responsive,human serum albumin,optical platform,bilirubin

    更新于2025-09-23 15:22:29

  • Encapsulation of zinc phthalocyanine into bovine serum albumin aggregates

    摘要: Artificial hybridization of molecules with proteins is beneficial for biomedical applications. Herein, we describe a novel method for encapsulation of zinc phthalocyanine (ZnPc) aggregates into bovine serum albumin (BSA) aggregates, but not monomeric BSA. This property is potentially useful for not only photodynamic or photothermal therapy but also development of a novel delivery system for hydrophobic drug molecules.

    关键词: Gel-filtration chromatography,Photosensitizer,Aggregation,Bovine serum albumin,Phthalocyanine,Photodynamic therapy

    更新于2025-09-23 15:22:29

  • Synthesis, Anticonvulsant and Binding Interaction Study of Novel Piperamides with Bovine Serum Albumin by Fluorescence Spectroscopy

    摘要: A series of piperamides (PA) 8a-j were designed, synthesized and evaluated for their antimicrobial and anticonvulsant activity. Compounds 8a and 8h showed considerable antibacterial activity against B. subtilis with minimum inhibitory concentration (MIC) of 8 and 10 μg/mL, respectively. Compounds 8a and 8h showed advanced anticonvulsant activity as well as lower neurotoxicity than the reference drugs. The interaction between bovine serum albumin (BSA) and PA was investigated using fluorescence quenching and UV-vis absorption spectroscopy. Results showed that PA could strongly quench the intrinsic fluorescence of BSA through a static quenching procedure. The binding constant and number of binding sites of PA with BSA were obtained. The binding distance was calculated based on Forster non-radiative energy transfer theory.

    关键词: Anticonvulsant,bovine serum albumin,fluorescence quenching,piperamide

    更新于2025-09-23 15:22:29

  • Spontaneous Charge Generation in Flowing Albumin Solutions at 35 °C and 38 °C

    摘要: The time dependence of a charge accumulation in a 10?15 M albumin solution, flowing through a measuring cell of an analytical flow system injector, had a nonlinear character under certain conditions, within a human physiological temperature range. Sharp charge increases depended on albumin concentration. This effect must be taken into consideration when generating models that describe electrokinetic phenomena in flowing protein solutions and when developing analytical flow systems for the registration of biomolecules in low concentration ranges.

    关键词: flowing protein solution,charge accumulation,analytical flow-through systems,physiological temperature,serum albumin

    更新于2025-09-23 15:22:29

  • Protein Corona Formation of Human Serum Albumin with Carbon Quantum Dots from Roasted Salmon

    摘要: As the food-borne nanoparticles enter the biological system, they will contact with various proteins to form protein coronas, which can affect their physicochemical properties and biological identity. In this study, the protein corona formation of carbon quantum dots (CQDs) from roast salmon with human serum albumin (HSA), as well as biological identity involving cell apoptosis, energy, glucose and lipid metabolism and acute toxicity in mice, were investigated. The HSA-CQD coronas formed between HSA and CQDs via static binding mechanism, and the binding site of CQDs on HSA located both in Sudlow’s site I and site II. The HSA-CQD coronas entered the cytoplasm and present in lysosomes or autolysosomes. Importantly, the HSA coronas mitigated the cytotoxicity of CQDs from 18.65% to 9.26%, and the energy metabolism was rectified from glycolytic to aerobic metabolism. The glucose and lipid metabolite profile of the HSA-CQD coronas differed from that of the CQDs, indicating that HSA-CQD coronas rectified disturbance in metabolism. Histopathological and blood biochemical analysis revealed no statistically significant difference between the testing and control mice after a single CQDs dose of 2000 mg/kg body weight. Overall, the results confirmed the formation of protein corona between HSA and food-borne fluorescent CQDs, and could be helpful for evaluating the safety of fluorescent CQDs from roast food items.

    关键词: cytotoxicity,acute toxicity,protein coronas,human serum albumin,carbon quantum dots,metabolism,food-borne nanoparticles

    更新于2025-09-23 15:21:01