Rapid monitoring of black tea fermentation quality based on a solution-phase sensor array combined with UV-visible spectroscopy

We demonstrate the fabrication and nonlinear optical (NLO) characterization of chalcogenide glass thin films obtained from the solution phase driven approach. The characterization of the films was ahieved using FESEM, AFM, micro-Raman, FTIR, UV-Visible spectroscopy, optical profilometry and XRD. The NLO studies were performed on the solution driven and thermally deposited As2S3 films with [Formula: see text]2[Formula: see text]ps, 800[Formula: see text]nm laser pulses using the Z-scan technique. The results obtained from AFM measurements demonstrated that the surface roughness of the film was considerably low ([Formula: see text]2[Formula: see text]nm) and Z-scan data indicated that the nonlinear refractive index was in the 1.0–[Formula: see text][Formula: see text]m2/W range.

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Biocompatibility of Silver Nano Bio-conjugates from Vitis vinifera Seeds and its Major Component Resveratrol

International Journal of Drug Delivery Technology ◽

10.25258/ijddt.v6i3.8896 ◽

2016 ◽

Vol 6 (3) ◽

Author(s):

R. Preethi ◽

P. Padma

Keyword(s):

Zeta Potential ◽

Vitis Vinifera ◽

Silver Ions ◽

Seed Extract ◽

Polydispersity Index ◽

Potential Range ◽

Visible Spectroscopy ◽

Grape Seeds ◽

X Ray ◽

Uv Visible

The study focused on the green synthesis of silver nanobioconjugates (AgNPs) from phenolic-rich fruit source, Vitis vinifera seed extract and its major component phenolic, resveratrol respectively. Sunlight exposure for 20 minutes was the method of choice for the synthesis of AgNPs of the extract as well as the phenolic, resveratrol. The synthesized nanobioconjugates were characterized using UV-Visible spectroscopy, Transmission electron microscopy (TEM), Energy dispersive X-ray analysis (EDAX), X-ray diffraction (XRD), Polydispersity index, Zeta potential and Fourier transform infrared spectroscopy (FTIR). The reduction of silver ions was confirmed by UV-visible spectroscopy with peaks at 440nm for both nanobioconjugates synthesized from seed extract and compound. The nanobioconjugates showed the spherical in shape with 14-35nm in size and crystalline in nature. The conjugates are well dispersed with 0.301 and 0.287 polydispersity index and the zeta potential range at -13.6 and -14.3mV for stability. The FTRI data proved that the components in grape seeds act as good reductants and stabilizers for the silver nanobioconjugate synthesis. All the synthesized nanobioconjugates exhibited steady and sustained release of the medicinal components conjugated, proving their druggability, and were biocompatible with human cells, demonstrating their safety. The findings of the study validate the anticancer properties of silver nanobioconjugates of Vitis vinifera and its active component resveratrol.

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Evaluation of Antibacterial and Antidiabetic Potential of Silver Nanoparticles using Eugenia Uniflora L. Seed Extract

International Journal of Pharmaceutical Sciences and Nanotechnology ◽

10.37285/ijpsn.2020.13.6.6 ◽

2020 ◽

Vol 13 (6) ◽

pp. 5217-5225

Author(s):

Guru Kumar Dugganaboyana ◽

Chethankumar Mukunda ◽

Suresh Darshini Inakanally

Keyword(s):

Biomedical Applications ◽

Pathogenic Bacteria ◽

Seed Extract ◽

Drug Formulation ◽

Visible Spectroscopy ◽

Plant Materials ◽

X Ray ◽

Eugenia Uniflora ◽

Uv Visible

In recent years, green nanotechnology-based approaches using plant materials have been accepted as an environmentally friendly and cost-effective approach with various biomedical applications. In the current study, AgNPs were synthesized using the seed extract of the Eugenia uniflora L. (E.uniflora). Characterization was done using UV-Visible spectroscopy, X-ray diffraction (XRD), scanning electronic microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) analyses. The formation of AgNPs has confirmed through UV-Visible spectroscopy (at 466 nm) by the change of color owing to surface Plasmon resonance. Based on the XRD pattern, the crystalline property of AgNPs was established. The functional group existing in seed of E.uniflora extract accountable for the reduction of Ag+ ion and the stabilization of AgNPs was investigated. The morphological structures and elemental composition was determined by SEM and EDX analysis. With the growing application of AgNPs in biomedical perspectives, the biosynthesized AgNPs were evaluated for their antibacterial and along with their antidiabetic potential. The results showed that AgNPs are extremely effective with potent antidiabetic potential at a very low concentration. It also exhibited potential antibacterial activity against the three tested human pathogenic bacteria. Overall, the results highlight the effectiveness and potential applications of AgNPs in biomedical fields such as in the treatment of acute illnesses as well as in drug formulation for treating various diseases such as cancer and diabetes. It could be concluded that E. uniflora seed extract AgNPs can be used efficiently for in vitro evaluation of their antibacterial and antidiabetic effects with potent biomedical applications.

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Polymer Composites with 0.98 Transparencies and Small Optical Energy Band Gap Using a Promising Green Methodology: Structural and Optical Properties

Polymers ◽

10.3390/polym13101648 ◽

2021 ◽

Vol 13 (10) ◽

pp. 1648

Author(s):

Muaffaq M. Nofal ◽

Shujahadeen B. Aziz ◽

Jihad M. Hadi ◽

Wrya O. Karim ◽

Elham M. A. Dannoun ◽

...

Keyword(s):

Refractive Index ◽

Optical Properties ◽

Polymer Composites ◽

Amorphous Phase ◽

Absorption Edge ◽

Complex Form ◽

Bandgap Energy ◽

Optical Parameters ◽

Visible Spectroscopy ◽

Uv Visible

In this work, a green approach was implemented to prepare polymer composites using polyvinyl alcohol polymer and the extract of black tea leaves (polyphenols) in a complex form with Co2+ ions. A range of techniques was used to characterize the Co2+ complex and polymer composite, such as Ultraviolet–visible (UV-Visible) spectroscopy, Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The optical parameters of absorption edge, refractive index (n), dielectric properties including real and imaginary parts (εr, and εi) were also investigated. The FRIR and XRD spectra were used to examine the compatibility between the PVA polymer and Co2+-polyphenol complex. The extent of interaction was evidenced from the shifts and change in the intensity of the peaks. The relatively wide amorphous phase in PVA polymer increased upon insertion of the Co2+-polyphenol complex. The amorphous character of the Co2+ complex was emphasized with the appearance of a hump in the XRD pattern. From UV-Visible spectroscopy, the optical properties, such as absorption edge, refractive index (n), (εr), (εi), and bandgap energy (Eg) of parent PVA and composite films were specified. The Eg of PVA was lowered from 5.8 to 1.82 eV upon addition of 45 mL of Co2+-polyphenol complex. The N/m* was calculated from the optical dielectric function. Ultimately, various types of electronic transitions within the polymer composites were specified using Tauc’s method. The direct bandgap (DBG) treatment of polymer composites with a developed amorphous phase is fundamental for commercialization in optoelectronic devices.

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Green synthesis of silk sericin-embedded silver nanoparticles and their antibacterial application against multidrug-resistant pathogens

Journal of Genetic Engineering and Biotechnology ◽

10.1186/s43141-021-00176-5 ◽

2021 ◽

Vol 19 (1) ◽

Author(s):

Md. Abdullah Al Masud ◽

Hamid Shaikh ◽

Md. Shamsul Alam ◽

M. Minnatul Karim ◽

M. Abdul Momin ◽

...

Keyword(s):

Silver Nanoparticles ◽

Green Synthesis ◽

Bombyx Mori ◽

Multidrug Resistant ◽

Visible Spectroscopy ◽

Silk Sericin ◽

X Ray ◽

Synthesis Strategy ◽

Uv Visible ◽

Multidrug Resistant Pathogens

Abstract Background The green synthesis strategy of metallic nanoparticles (NPs) has become popular due to being environmentally friendly. Stable silver nanoparticles (AgNPs) have been synthesized by natural products such as starch, soy protein, various extract of leaves, barks, and roots functioning both as reducing and stabilizing agents. Likewise, silk sericin (SS) is a globular protein discarded in the silk factory might be used for NP synthesis. In this research, we focus on the green synthesis and stabilization of AgNPs by SS as well as assessment of their antibacterial activities against some drug-resistant pathogen. Results SS was extracted from Bombyx mori silkworm cocoons in an aqueous medium. 17 w/w% of dry sericin powder with respect to the cocoon’s weight was obtained by freeze-drying. Furthermore, AgNPs conjugated to sericin, i.e., SS-capped silver nanoparticles (SS-AgNPs) were synthesized by easy, cost-effective, and environment-friendly methods. The synthesized SS-AgNPs were characterized by UV-visible spectroscopy, Fourier-transform infrared-attenuated total reflection (FTIR-ATR) spectroscopy, transmission electron microscopy (TEM), and X-ray diffraction measurement. It has been found from the absorbance of UV-visible spectroscopy that a higher percent of SS-AgNPs was obtained at a higher concentration of silver nitrate solution. FTIR-ATR spectra showed that the carboxylate groups obtained from silk sericin act as a reducing agent for the synthesis of silver nanoparticles, while NH2+ and COO− act as a stabilizer of AgNPs. The X-ray diffractogram of SS-AgNPs was quite different from AgNO3 and sericin due to a change in the crystal structure. The diameter of AgNPs was around 20–70 nm observed using TEM. The synthesized SS-AgNPs exhibited strong antibacterial activity against multidrug-resistant pathogens, Escherichia coli and Pseudomonas aeruginosa. Minimal inhibitory/bactericidal concentrations against E. coli and P. aeruginosa were 20μg/mL. Conclusions This study encourages the use of Bombyx mori for the ecofriendly synthesis of SS-AgNPs to control multidrug-resistant microorganisms.

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Optical and Photoacoustic Properties of Laser-Ablated Silver Nanoparticles in a Carbon Dots Solution

Molecules ◽

10.3390/molecules25245798 ◽

2020 ◽

Vol 25 (24) ◽

pp. 5798

Author(s):

Amir Reza Sadrolhosseini ◽

Ganesan Krishnan ◽

Suhaidi Shafie ◽

Suraya Abdul Rashid ◽

Sulaiman Wadi Harun

Keyword(s):

Silver Nanoparticles ◽

Carbon Dots ◽

Thermal Effusivity ◽

Nonlinear Susceptibility ◽

Time Range ◽

Raman Signal ◽

Optical Parameters ◽

Visible Spectroscopy ◽

Transmission Electron ◽

Uv Visible

This study used the carbon dots solution for the laser ablation technique to fabricate silver nanoparticles. The ablation time range was from 5 min to 20 min. Analytical methods, including Fourier transform infrared spectroscopy (FTIR), UV-visible spectroscopy, transmission electron microscopy, and Raman spectroscopy were used to categorize the prepared samples. The UV-visible and z-scan techniques provided optical parameters such as linear and nonlinear refractive indices in the range of 1.56759 to 1.81288 and 7.3769 × 10−10 cm2 W−1 to 9.5269 × 10−10 cm2 W−1 and the nonlinear susceptibility was measured in the range of 5.46 × 10−8 to 6.97 × 10−8 esu. The thermal effusivity of prepared samples, which were measured using the photoacoustic technique, were in the range of 0.0941 W s1/2 cm−2 K−1 to 0.8491 W s1/2 cm−2 K−1. The interaction of the prepared sample with fluoride was investigated using a Raman spectrometer. Consequently, the intensity of the Raman signal decreased with the increasing concentration of fluoride, and the detection limit is about 0.1 ppm.

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Evaluation of N-Alkyl-bis-o-aminobenzamide Receptors for the Determination and Separation of Metal Ions by Fluorescence, UV-Visible Spectrometry and Zeta Potential

Molecules ◽

10.3390/molecules24091737 ◽

2019 ◽

Vol 24 (9) ◽

pp. 1737 ◽

Cited By ~ 1

Author(s):

Marisela Martinez-Quiroz ◽

Xiomara E. Aguilar-Martinez ◽

Mercedes T. Oropeza-Guzman ◽

Ricardo Valdez ◽

Eduardo A. Lopez-Maldonado

Keyword(s):

Aqueous Solution ◽

Zeta Potential ◽

Metal Ions ◽

Environmental Concern ◽

Separation Of Metal Ions ◽

Complexing Capacity ◽

Alkyl Groups ◽

Molecular Fluorescence ◽

Uv Visible ◽

Phase Sensor

This paper presents the synthesis and evaluation of physicochemical behavior of a new series of N-alkyl-bis-o-aminobenzamides (BOABs) in aqueous solution. The study was targeted to the complexing capacity of five metal ions (Fe2+, Cu2+, Cd2+, Hg2+ and Pb2+) of environmental concern as the medullar principle of a liquid phase sensor for its application in the determination of these metal ions due to its versatility of use. Molecular fluorescence, UV-visible and Zeta potential were measured for five BOABs and the effect of alkyl groups with different central chain length (n = 3, 4, 6, 8 and 10) on physicochemical performance determined. The results have shown that these derivatives present higher sensibility and selectivity for Cu2+ even in the presence of the other metal ions. An additional application test was done adding a pectin (0.1 wt %) solution to the BOAB-Cu+2 complex to obtain a precipitate (flocs) as a potential selective separation process of Cu from aqueous solution. The solid was then lyophilized and analyzed by SEM-EDS, the images showed spheric forms containing Cu+2 with diameter of approximately of 8 μm and 30 wt %.

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