The Experts below are selected from a list of 189 Experts worldwide ranked by ideXlab platform

Lilia Coronato Courrol - One of the best experts on this subject based on the ideXlab platform.

  • PegylatedCurcumin with Gold Nanoparticles: Antimicrobial Agent Evaluation
    2016
    Co-Authors: Daniella Dos Santos Courrol, Bruna Henrique Teixeira, Camila Bueno Pacheco Pereira, Marcia Regina Franzolin, Lilia Coronato Courrol
    Abstract:

    Extended Abstract Curcumin is a polyphenol derived from the Curcuma Longa plant. Curcumin exhibits a variety of therapeutic properties, including antioxidant, analgesic, anti-inflammatory, anticancer and antiseptic activities [1]. Curcumin acts as photosensitizer in photodynamic therapy (PDT), which is an alternative way to kill pathogenic microorganisms [2]. The use of gold nanoparticles (AuNPs) as the vehicle for curcumin delivery increases photodynamic ability [3]. Therefore, the present study aim is to investigate the effect of the photodynamic action of LED-activated curcumin gold nanoparticles, on cell viability of Staphylococcus aureus, Staphylococcus aureus (Sa), Staphylococcus epidermidis (Se), Pseudomonas aeruginosa (Pa), Escherichia coli (Ec), Citrobacter freundii (Cf) and Klebsiella pneumoniae (Kp). To prepare Curcumin gold nanoparticles (Curc:AuNps) solutions, 3.2 mg of HAuCl4 was mixed with 1.5 mg Curcumin and Polyethylene glycol (PEG) in Mili-Q water. This solution was exposed to light from a Mercury Metal halide lamp. The resulting solutions were characterized by UV-Vis and transmission electron microscopy (TEM). The in vitro antibacterial activity of Curc:AuNps was evaluated against Sa, Se, Pa, Ec, Cf and Kp using the minimum inhibitory concentration (MIC) test. The effects of exposure to yellow LED light with ~38 J/cm fluence and variations in the Curc:AuNPs concentrations (50, 75 and 100% dilutions) were studied. The presence of a surface plasmon resonance band at ~520 nm indicated the formation of spherical gold nanoparticles. In the presence of PEG, the solution color changed some minutes after the mixing of reagents, and solution size homogeneity was improved with the Mercury Metal halide lamp illumination. TEM analyses showed ~17±2 nm nanoparticles. The results indicate that PDT with curcumin gold nanoparticles strongly inhibits the development of Gram positive and Gram negative bacteria. This study revealed antibacterial probability of inhibition >80% with 32 mM of Curc:AuNPs and light against Sa, Se, Cf and Kp strains after 18 hours of incubation. NOVA/Tukey's tests were conducted to compare groups curcumin/Curc:AuNPs, with and without photodynamic excitation. This work was supported by the “Fundacao de Amparo a Pesquisa do Estado de Sao Paulo” (FAPESP), Grant number 2014/06960-9.

  • Saliva and light as templates for the green synthesis of silver nanoparticles
    Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2014
    Co-Authors: Ricardo Almeida De Matos, Lilia Coronato Courrol
    Abstract:

    Abstract We report a method for the synthesis of silver nanoparticles using an aqueous saliva solution and irradiation with light from a Mercury Metal halide lamp. Bi-deionized water was used as the solvent, and surfactants or reducing agents were substituted by saliva and light in the procedure, characterizing the process as a “green” synthesis. The light was used to reduce silver ions (Ag+) to Metallic silver (Ag0). The average size, size distribution, and morphology of the nanoparticles were determined by transmission electron microscopy (TEM), UV/visible absorption spectrophotometry and Fourier transform infrared spectroscopy (FTIR). Spherical nanoparticles of ∼20 nm in size were present after the lamp illumination. This methodology represents a non-invasive approach for disease detection and possesses a good potential for diagnostics applications.

  • Saliva and light as templates for the green synthesis of silver nanoparticles
    Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2014
    Co-Authors: Ricardo Almeida De Matos, Lilia Coronato Courrol
    Abstract:

    We report a method for the synthesis of silver nanoparticles using an aqueous saliva solution and irradiation with light from a Mercury Metal halide lamp. Bi-deionized water was used as the solvent, and surfactants or reducing agents were substituted by saliva and light in the procedure, characterizing the process as a "green" synthesis. The light was used to reduce silver ions (Ag+) to Metallic silver (Ag0). The average size, size distribution, and morphology of the nanoparticles were determined by transmission electron microscopy (TEM), UV/visible absorption spectrophotometry and Fourier transform infrared spectroscopy (FTIR). Spherical nanoparticles of ~20nm in size were present after the lamp illumination. This methodology represents a non-invasive approach for disease detection and possesses a good potential for diagnostics applications. © 2013 Elsevier B.V.

Ashok Kumar Singh - One of the best experts on this subject based on the ideXlab platform.

  • Chromogenic ‘naked eye’ and fluorogenic ‘turn on’ sensor for Mercury Metal ion using thiophene-based Schiff base
    RSC Advances, 2020
    Co-Authors: Divya Singhal, Neha Gupta, Ashok Kumar Singh
    Abstract:

    2-((3-Methylthiophen-2-yl)methyleneamino)benzenethiol (Probe 1) has been synthesized and successfully applied for the selective recognition of Mercury Metal ions and utilized as a fluorescence turn-on sensor for Hg2+ ion via chelation enhanced fluorescence (CHEF). The mechanism of the interaction of Probe 1 with Metal ions has been deduced by the absorption, emission, 1H-NMR, and MALDI-TOF Mass analysis that intimate the favourable coordination of Hg2+ Metal ion by the mercapto unit. The 2 : 1 stoichiometry of the sensor complex 1 + Hg2+ was calculated from the Job’s plot based on UV-Vis absorption spectra. The binding constant (log β2) of the 1 + Hg2+ complex was found to be 13.36 by Hill plot. The limit of detection (LOD) was also calculated from the fluorescence emission titration and found to be 20 μM. Moreover the density functional theory (DFT) studies were investigated for the 1 + Hg2+ binding mechanism. Cyclic voltammograms also confirmed the recognition of Hg2+ Metal ion to the Probe 1.

  • chromogenic naked eye and fluorogenic turn on sensor for Mercury Metal ion using thiophene based schiff base
    RSC Advances, 2015
    Co-Authors: Divya Singhal, Neha Gupta, Ashok Kumar Singh
    Abstract:

    2-((3-Methylthiophen-2-yl)methyleneamino)benzenethiol (Probe 1) has been synthesized and successfully applied for the selective recognition of Mercury Metal ions and utilized as a fluorescence turn-on sensor for Hg2+ ion via chelation enhanced fluorescence (CHEF). The mechanism of the interaction of Probe 1 with Metal ions has been deduced by the absorption, emission, 1H-NMR, and MALDI-TOF Mass analysis that intimate the favourable coordination of Hg2+ Metal ion by the mercapto unit. The 2 : 1 stoichiometry of the sensor complex 1 + Hg2+ was calculated from the Job’s plot based on UV-Vis absorption spectra. The binding constant (log β2) of the 1 + Hg2+ complex was found to be 13.36 by Hill plot. The limit of detection (LOD) was also calculated from the fluorescence emission titration and found to be 20 μM. Moreover the density functional theory (DFT) studies were investigated for the 1 + Hg2+ binding mechanism. Cyclic voltammograms also confirmed the recognition of Hg2+ Metal ion to the Probe 1.

Divya Singhal - One of the best experts on this subject based on the ideXlab platform.

  • Chromogenic ‘naked eye’ and fluorogenic ‘turn on’ sensor for Mercury Metal ion using thiophene-based Schiff base
    RSC Advances, 2020
    Co-Authors: Divya Singhal, Neha Gupta, Ashok Kumar Singh
    Abstract:

    2-((3-Methylthiophen-2-yl)methyleneamino)benzenethiol (Probe 1) has been synthesized and successfully applied for the selective recognition of Mercury Metal ions and utilized as a fluorescence turn-on sensor for Hg2+ ion via chelation enhanced fluorescence (CHEF). The mechanism of the interaction of Probe 1 with Metal ions has been deduced by the absorption, emission, 1H-NMR, and MALDI-TOF Mass analysis that intimate the favourable coordination of Hg2+ Metal ion by the mercapto unit. The 2 : 1 stoichiometry of the sensor complex 1 + Hg2+ was calculated from the Job’s plot based on UV-Vis absorption spectra. The binding constant (log β2) of the 1 + Hg2+ complex was found to be 13.36 by Hill plot. The limit of detection (LOD) was also calculated from the fluorescence emission titration and found to be 20 μM. Moreover the density functional theory (DFT) studies were investigated for the 1 + Hg2+ binding mechanism. Cyclic voltammograms also confirmed the recognition of Hg2+ Metal ion to the Probe 1.

  • chromogenic naked eye and fluorogenic turn on sensor for Mercury Metal ion using thiophene based schiff base
    RSC Advances, 2015
    Co-Authors: Divya Singhal, Neha Gupta, Ashok Kumar Singh
    Abstract:

    2-((3-Methylthiophen-2-yl)methyleneamino)benzenethiol (Probe 1) has been synthesized and successfully applied for the selective recognition of Mercury Metal ions and utilized as a fluorescence turn-on sensor for Hg2+ ion via chelation enhanced fluorescence (CHEF). The mechanism of the interaction of Probe 1 with Metal ions has been deduced by the absorption, emission, 1H-NMR, and MALDI-TOF Mass analysis that intimate the favourable coordination of Hg2+ Metal ion by the mercapto unit. The 2 : 1 stoichiometry of the sensor complex 1 + Hg2+ was calculated from the Job’s plot based on UV-Vis absorption spectra. The binding constant (log β2) of the 1 + Hg2+ complex was found to be 13.36 by Hill plot. The limit of detection (LOD) was also calculated from the fluorescence emission titration and found to be 20 μM. Moreover the density functional theory (DFT) studies were investigated for the 1 + Hg2+ binding mechanism. Cyclic voltammograms also confirmed the recognition of Hg2+ Metal ion to the Probe 1.

Ricardo Almeida De Matos - One of the best experts on this subject based on the ideXlab platform.

  • Saliva and light as templates for the green synthesis of silver nanoparticles
    Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2014
    Co-Authors: Ricardo Almeida De Matos, Lilia Coronato Courrol
    Abstract:

    Abstract We report a method for the synthesis of silver nanoparticles using an aqueous saliva solution and irradiation with light from a Mercury Metal halide lamp. Bi-deionized water was used as the solvent, and surfactants or reducing agents were substituted by saliva and light in the procedure, characterizing the process as a “green” synthesis. The light was used to reduce silver ions (Ag+) to Metallic silver (Ag0). The average size, size distribution, and morphology of the nanoparticles were determined by transmission electron microscopy (TEM), UV/visible absorption spectrophotometry and Fourier transform infrared spectroscopy (FTIR). Spherical nanoparticles of ∼20 nm in size were present after the lamp illumination. This methodology represents a non-invasive approach for disease detection and possesses a good potential for diagnostics applications.

  • Saliva and light as templates for the green synthesis of silver nanoparticles
    Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2014
    Co-Authors: Ricardo Almeida De Matos, Lilia Coronato Courrol
    Abstract:

    We report a method for the synthesis of silver nanoparticles using an aqueous saliva solution and irradiation with light from a Mercury Metal halide lamp. Bi-deionized water was used as the solvent, and surfactants or reducing agents were substituted by saliva and light in the procedure, characterizing the process as a "green" synthesis. The light was used to reduce silver ions (Ag+) to Metallic silver (Ag0). The average size, size distribution, and morphology of the nanoparticles were determined by transmission electron microscopy (TEM), UV/visible absorption spectrophotometry and Fourier transform infrared spectroscopy (FTIR). Spherical nanoparticles of ~20nm in size were present after the lamp illumination. This methodology represents a non-invasive approach for disease detection and possesses a good potential for diagnostics applications. © 2013 Elsevier B.V.

Neha Gupta - One of the best experts on this subject based on the ideXlab platform.

  • Chromogenic ‘naked eye’ and fluorogenic ‘turn on’ sensor for Mercury Metal ion using thiophene-based Schiff base
    RSC Advances, 2020
    Co-Authors: Divya Singhal, Neha Gupta, Ashok Kumar Singh
    Abstract:

    2-((3-Methylthiophen-2-yl)methyleneamino)benzenethiol (Probe 1) has been synthesized and successfully applied for the selective recognition of Mercury Metal ions and utilized as a fluorescence turn-on sensor for Hg2+ ion via chelation enhanced fluorescence (CHEF). The mechanism of the interaction of Probe 1 with Metal ions has been deduced by the absorption, emission, 1H-NMR, and MALDI-TOF Mass analysis that intimate the favourable coordination of Hg2+ Metal ion by the mercapto unit. The 2 : 1 stoichiometry of the sensor complex 1 + Hg2+ was calculated from the Job’s plot based on UV-Vis absorption spectra. The binding constant (log β2) of the 1 + Hg2+ complex was found to be 13.36 by Hill plot. The limit of detection (LOD) was also calculated from the fluorescence emission titration and found to be 20 μM. Moreover the density functional theory (DFT) studies were investigated for the 1 + Hg2+ binding mechanism. Cyclic voltammograms also confirmed the recognition of Hg2+ Metal ion to the Probe 1.

  • chromogenic naked eye and fluorogenic turn on sensor for Mercury Metal ion using thiophene based schiff base
    RSC Advances, 2015
    Co-Authors: Divya Singhal, Neha Gupta, Ashok Kumar Singh
    Abstract:

    2-((3-Methylthiophen-2-yl)methyleneamino)benzenethiol (Probe 1) has been synthesized and successfully applied for the selective recognition of Mercury Metal ions and utilized as a fluorescence turn-on sensor for Hg2+ ion via chelation enhanced fluorescence (CHEF). The mechanism of the interaction of Probe 1 with Metal ions has been deduced by the absorption, emission, 1H-NMR, and MALDI-TOF Mass analysis that intimate the favourable coordination of Hg2+ Metal ion by the mercapto unit. The 2 : 1 stoichiometry of the sensor complex 1 + Hg2+ was calculated from the Job’s plot based on UV-Vis absorption spectra. The binding constant (log β2) of the 1 + Hg2+ complex was found to be 13.36 by Hill plot. The limit of detection (LOD) was also calculated from the fluorescence emission titration and found to be 20 μM. Moreover the density functional theory (DFT) studies were investigated for the 1 + Hg2+ binding mechanism. Cyclic voltammograms also confirmed the recognition of Hg2+ Metal ion to the Probe 1.