A label-free multicolor colorimetric and fluorescence dual mode biosensing of HIV-1 DNA based on the bifunctional NiFe2O4@UiO-66 nanozyme.

Finding the DNA of the human immune deficiency virus (HIV) with simple and sensitive detection is the main challenge in early diagnosis of AIDS. Herein, two-point separation strategies based on the colorimetric and fluorescence are introduced. The naked-eye qualitative and semiquantitative colorimetric, and also accuracy fluorescence quantification of HIV-1 DNA were applied using label-free NiFe2O4@UiO-66 nanozyme with both functions of peroxidase-mimetic like and emitting fluorescence. The DNA probe-conjugated nanozyme is employed to hybridize a sequence of HIV-1. NiFe2O4@UiO-66 nanozymes catalyze the decomposition of H2O2 to •OH which can produce a remarkable fluorescent product 2-hydroxyterephthalic acid (TAOH) by the oxidation of the bridging ligand of weakly fluorescent terephthalic acid (TA). The accessibility of H2O2 toward confined-NiFe2O4 MNPs was reduced by increasing the HIV-1 target DNA concentration, resulting in the fluorescence intensity of TAOH being decreased. Meanwhile, remaining the unreacted H2O2 was transferred an acidic colorimetric solution containing FeSO4 and gold nanorods (AuNRs). Increasing the amount of H2O2 available for longitudinal etching of AuNRs due to •OH-generating Fe+2-catalyzed H2O2 is reponsible for different colors from brownish to colorless depending on the HIV-1 target DNA concentration. The fluorescence intensity and obtained colors have offered the sensitive biosensing methods with a linear range from 0.05 to 300 and 1-200 pM, respectively with a detection limit as low as 1 fM. Our study revealed that the applied sensing assay provides a cost-effective and straightforward qualitative, semiquantitative, and sensitive quantitation visible monitoring without the necessity of high-end instruments for HIV-1 detection in a human blood plasma/serum samples.

Biochemical, Ameliorative and Cytotoxic Effects of Newly Synthesized Curcumin Microemulsions: Evidence from In Vitro and In Vivo Studies.

Curcumin is known to exhibit antioxidant and tissue-healing properties and has recently attracted the attention of the biomedical community for potential use in advanced therapies. This work reports the formulation and characterization of oil-in-water F127 microemulsions to enhance the bioavailability of curcumin Microemulsions showed a high encapsulation efficiency and prolonged release. To investigate the interactions of curcumin with one unit of the polymeric chain of surfactant F127, ethyl butyrate, and sodium octanoate, as well as the interaction between ethyl butyrate and one unit of the F127 polymer chain, the Density Functional Theory (DFT) calculations at the M06-2X level of theory, were performed in water solution. The MTT assay was used to assess the cytotoxicity of free and encapsulated curcumin on non-malignant and malignant cell lines. Combination effects were calculated according to Chou-Talalay's principles. Results of in vitro studies indicated that MCF7 and HepG2 cells were more sensitive to curcumin microemulsions. Moreover, a synergistic relationship was observed between curcumin microemulsions and cisplatin in all affected fractions of MCF7 and HepG2 cells (CI < 0.9). For in vivo investigation, thioacetamide-intoxicated rats received thioacetamide (100 mg/kg Sc) followed by curcumin microemulsions (30 mg/kg Ip). Thioacetamide-intoxicated rats showed elevated serum liver enzymes, blood urea nitrogen (BUN), and creatinine levels, and a significant reduction in liver superoxide dismutase (SOD) and catalase (CAT) activities (p < 0.05). Curcumin microemulsions reduced liver enzymes and serum creatinine and increased the activity of antioxidant enzymes in thioacetamide-treated rats in comparison to the untreated thioacetamide-intoxicated group. Histopathological investigations confirmed the biochemical findings. Overall, the current results showed the desirable hepatoprotective, nephroprotective, and anti-cancer effects of curcumin microemulsions.

Investigation on the Linear and Nonlinear Properties of Morin in Presence of Reverse Micelle and Different Oil Content in Reverse Micelle.

We investigate the linear and nonlinear optical property of Morin (MN) at different concentration (1 × 10-6 and 5 × 10-6 M) within AOT reversed micelle prepared by water-in-decane microemulsion having a constant molar ratio of water-to-surfactant molecules of 40 (W = [H2O]/[AOT] = 40) as well as the function of mass fraction of nano-droplet (MFD) values of 0.01,0.04, 0.07, and 0.1 by using UV-Visible, Fluorescence, FTIR, and Z-scan techniques. The steady-state measurement indicates that the presence of microenvironment can greatly affect the tautomeric structure of morin and also Morin property in microenvironment depends upon the amount of oil and Morin concentration. The increase in dipole moment from the ground state to excited state in microenvironment indicate the change in the molecular structure on morin. Morin does not show any nonlinear absorption property but the nonlinear refractive index is observed as a function of Morin concentration as well as MFD values which are due to the thermal agitation of formed dimers. Morin nonlinearity.

New porphyrins: synthesis, characterization, and computational studies.

New trans-A2B2-porphyrins substituted at phenyl positions were synthesized from 4-methylphthalic acid as a starting material through sequential multistep reactions. These macrocycles were characterized by 1H NMR, 13C NMR, 19F NMR, 1H-1H COSY NMR, and MALDI-TOF mass spectrometry. Computational studies were performed on the porphyrins to investigate various factors such as structural features, electronic energy, energy gaps, and aromaticity. Energy band gap values of these compounds especially N-hydroxyphthalimide-functionalized porphyrins were small that makes them as good candidates for solar cell systems and photocatalysis. Relationships between electronic energies and aromaticity of the compounds were then investigated. The data indicated that the aromaticity features at the center of two series of these compounds (fluorinated and non-fluorinated porphyrins) were in the opposite manner.

Investigation of interactions of Comtan with human serum albumin by mathematically modeled voltammetric data: A study from bio-interaction to biosensing.

In this work, voltammetric data recorded at a glassy carbon electrode (GCE) were separately used to investigate the interactions of entacapone (Comtan, CAT) with human serum albumin (HSA). Then, an augmented data matrix was constructed by the combination of voltammetric and spectroscopic data and simultaneously analysed by multivariate curve resolution-alternating least squares (MCR-ALS) to obtain more information about CAT-HSA interactions. The absence of rotational ambiguities in results obtained by MCR-ALS was verified with the help of MCR-BANDS and we confirmed that the results were unambiguous and reliable. Binding of CAT to HSA was also modeled by molecular docking and the results were compatible with those of obtained by recording experimental data. Hard-modeling of combined voltammetric and spectroscopic data by EQUISPEC as an efficient chemometric algorithm helped us to compute binding constant of CAT-HSA complex specie which was in a good agreement with the binding constant value obtained by direct analysis of experimental data. For electrochemical sensing of serum albumin two amperometric measurements were performed to determine HSA in 2-27 nM and 27-70 nM with a limit of detection of 0.51 nM and a sensitivity of 1.84 µA nM-1.

In vitro antibacterial effects of silver nanoparticles synthesized using Verbena officinalis leaf extract on Yersinia ruckeri, Vibrio cholera and Listeria monocytogenes.

BACKGROUND AND OBJECTIVES: The use of plants for the synthesis of nanoparticles has received attention. The present study aimed to evaluate the antibacterial effects of silver nanoparticles synthesized by Verbena officinalis leaf extract against Yersinia ruckeri, Vibrio cholerae and Listeria monocytogenes. MATERIALS AND METHODS: Silver nanoparticles were obtained by reacting silver nitrate solution 2 mM and V. officinalis leaf extract. The AgNPs were characterized by UV-visible spectrophotometer, scanning electron microscopy (SEM), and Fourier transform infrared spectrometer (FTIR). To determine minimum inhibitory concentration and test antibiogram of nanoparticle synthesized, broth micro dilution and agar well diffusion methods were used, respectively. RESULTS: The zones of bacterial inhibition were 16 ± 0.5 and 9.16 ± 0.28 mm against Y. ruckeri and L. monocytogenes using 10 and 0.62 mg/mL AgNPs, respectively. Among the studied bacterial species, silver nanoparticles were more effective on Y. ruckeri and L. monocytogenes and less effective on V. cholerae. The highest MIC and MBC of AgNPs (2.5 and 5 mg/mL) were observed for V. cholerae. The lowest MIC and MBC of AgNPs (0.32 and 0.62 mg/mL) were observed for Y. ruckeri, respectively. The MIC and MBC of AgNPs were found to be 1.25 and 2.5 mg/mL for L. monocytogenes. CONCLUSION: The results clearly indicated that V. officinalis AgNPs have potential antimicrobial activity against Gram-positive and Gram-negative bacteria.

Silver nanoparticles as a new solid-phase adsorbent and its application to preconcentration and determination of lead from biological samples.

A new, simple, and fast method for preconcentration and determination of trace amount of lead from biological samples was developed by modified silver nanoparticle-based solid-phase extraction technique and graphite furnace atomic absorption spectrometry. In this study, morin was used as a complexing agent. Some factors influencing the recovery of lead including pH, sample flow rate, type, flow rate, and least amount of the eluent for elution of the lead from silver nanoparticles were studied and optimized. Under the optimum conditions, the detection limit of this method was 68 ng L(-1), and the relative standard deviation was 4.1% (n = 10, c = 20 µg L(-1)). The developed procedure was validated by the analysis of certified reference material and applied to the recovery and determination of lead in biological samples.

Development of a selective molecularly imprinted polymer-based solid-phase extraction for copper from food samples.

In this study is proposed a pre-concentration procedure using molecular imprinted polymer for the determination of copper in food samples. The copper imprinted polymer was prepared by free radical solution polymerization in a tube containing copper, morin, 4-vinylpyridine as a functional monomer, ethyleneglycoldimethacrylate as a cross-linking monomer, and 2,2'-azobisisobutyronitrile as an initiator. The polymer particles synthesized both before and after leaching have been characterized by infrared and X-ray diffraction studies. The effect of different variables such as pH of solution, adsorption and desorption time, type, and least amount of eluent for elution of the complex of polymer was evaluated. Extraction efficiencies more than 99% were obtained by elution of the polymer with 10 mL of 0.5 mol L(-1) EDTA. The detection limit of the proposed procedure was 0.14 microg L(-1). The method was applied to the determination of copper in food real samples.