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1.
Nanoscale Adv ; 6(1): 233-246, 2023 Dec 19.
Article in English | MEDLINE | ID: mdl-38125601

ABSTRACT

We have employed a co-precipitation method to synthesize different concentrations of carbon spheres (CSs) doped with cadmium sulfide (CdS) quantum dots (QDs) for catalytic reduction and antibacterial applications. Various morphological and structural characterization techniques were used to comprehensively analyze the CS effect on CdS QDs. The catalytic reduction efficiency of CS-doped CdS QDs was evaluated using rhodamine B dye. The antibacterial efficacy was also assessed against the pathogenic microorganism Escherichia coli (E. coli), and substantial destruction in the inhibitory zone was measured. Finally, the synthesized CS-doped CdS QDs demonstrated favorable results for catalytic reduction and antibacterial applications. Computational studies verified the suppressive impact of these formed QDs on DNA gyrase and ß-lactamase of E. coli.

2.
ACS Omega ; 8(40): 37564-37572, 2023 Oct 10.
Article in English | MEDLINE | ID: mdl-37841132

ABSTRACT

As the population grows, the scientific community remains focused on researching new materials, methods, and devices to ensure the availability of safe drinking water. The main aim of this research was to decrease the recombination rate of the charge carriers of La2O3 and enhance the catalytic and antimicrobial activity by employing Y/Cs- doped La2O3, respectively. In the current study, different concentrations of yttrium (Y) and a fixed amount of carbon spheres (Cs) doped into lanthanum oxide (La2O3) nanostructures (NSs) were synthesized by the coprecipitation technique. Cs are used as a cocatalyst as they have a high surface area and small size attributed to increased active sites and decreased recombination rate. Moreover, Y was further incorporated as it activates the generation of reactive oxygen species in the inhibition zone, enhancing the antibacterial activity and reducing the emission intensity. Advanced techniques were utilized to determine the structural properties, optical emission and absorption, elemental composition, and d-spacing of the synthesized samples. The reported ternary catalyst works efficiently, improving the catalytic activity and bactericidal potential. Moreover, in silico molecular docking studies, Cs-doped La2O3 and Y/Cs-doped La2O3 nanostructures toward DNA gyrase Escherichia coli showed good efficacy for antibacterial activity.

3.
RSC Adv ; 13(40): 28008-28020, 2023 Sep 18.
Article in English | MEDLINE | ID: mdl-37746345

ABSTRACT

In this research, a fixed concentration (3 wt%) of Ag/PAA and PAA/Ag doped graphene quantum dots (GQDs) were synthesized using the co-precipitation technique. A variety of characterization techniques were employed to synthesize samples to investigate their optical, morphological, structural, and compositional analyses, antimicrobial efficacy, and dye degradation potential with molecular docking analysis. GQDs have high solubility, narrow band gaps, and are suitable for electron acceptors and donors but show less adsorption and catalytic behavior. Incorporating polyacrylic acid (PAA) into GQDs increases the catalytic and antibacterial activities due to the carboxylic group (-COOH). Furthermore, introducing silver (Ag) increased the degradation of dye and microbes as it had a high surface-to-volume ratio. In addition, molecular docking studies were used to decipher the mechanism underlying the bactericidal action of silver and polyacrylic acid-doped graphene quantum dots and revealed inhibition of ß-lactamase and DNA gyrase.

4.
RSC Adv ; 13(37): 26149-26159, 2023 Aug 29.
Article in English | MEDLINE | ID: mdl-37664196

ABSTRACT

This research presents the novel synthesis of CeO2 nanostructures (NSs) doped with a fixed amount of capping agent (polyacrylic acid-PAA) and different concentrations (0.01 and 0.03) of silver (Ag). This work aimed to examine the catalytic and antibacterial efficacy with evidential molecular docking analysis of Ag/PAA doped CeO2. Systematic characterization was used to analyze the effect of Ag and a capping agent on crystal structure, morphology, absorbance wavelength, and the exciton recombination rate of CeO2. The silver metal and capping agent (PAA) were added into CeO2 to reduce the size of NSs, enhancing the catalytic efficacy. These binary dopants (Ag-PAA) based CeO2 revealed remarkable results for catalytic de-colorization of rhodamine B dye and antimicrobial potential as the dopants provide more active sites. Notably, (0.03) Ag/PAA doped CeO2 NSs exhibited a substantial catalytic reduction (98.9%) of rhodamine B dye in an acidic medium. The higher doped CeO2 revealed a significant inhibition zone (3.75 mm) against Escherichia coli at maximal concentration. Furthermore, in silico docking showed the possible inhibitory impact of produced nanomaterials on the fatty acid biosynthesis enzymes FabI and FabH.

5.
RSC Adv ; 13(36): 25305-25315, 2023 Aug 21.
Article in English | MEDLINE | ID: mdl-37622014

ABSTRACT

Herein, Bi2O3 quantum dots (QDs) have been synthesized and doped with various concentrations of graphitic carbon nitride (g-C3N4) and a fixed amount of carbon spheres (CS) using a co-precipitation technique. XRD analysis confirmed the presence of monoclinic structure along the space group P21/c and C2/c. Various functional groups and characteristic peaks of (Bi-O) were identified using FTIR spectra. QDs morphology of Bi2O3 showed agglomeration with higher amounts of g-C3N4 by TEM analysis. HR-TEM determined the variation in the d-spacing which increased with increasing dopants. These doping agents were employed to reduce the exciting recombination rate of Bi2O3 QDs by providing more active sites which enhance antibacterial activity. Notably, (6 wt%) g-C3N4/CS-doped Bi2O3 exhibited considerable antimicrobial potential in opposition to E. coli at higher values of concentrations relative to ciprofloxacin. The (3 wt%) g-C3N4/CS-doped Bi2O3 exhibits the highest catalytic potential (97.67%) against RhB in a neutral medium. The compound g-C3N4/CS-Bi2O3 has been suggested as a potential inhibitor of ß-lactamaseE. coli and DNA gyraseE. coli based on the findings of a molecular docking study that was in better agreement with in vitro bactericidal activity.

6.
Chemosphere ; 340: 139855, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37611764

ABSTRACT

Contaminants removal is usually becoming an exciting subject of research from water considering their environmental and ecological effects. This work provides pathways to remove organic pollutants from water via nanomaterials and is used as an antibiotic against bacteria like Escherichia coli (E. coli). In this study, molybdenum trioxide (MoO3) and yttrium (Y) doped (2 and 4%) MoO3 nanorods were synthesized by co-precipitation method. Advanced characterization techniques have been introduced to study textural structures, morphological developments, and optical characteristics of produced products. X-ray diffraction studied multiple crystalline structures of prepared samples as hexagonal, orthorhombic, and monoclinic of pure MoO3 with decrease in crystallinity and crystallite size upon Y doping. UV-visible spectroscopy unveiled a redshift (bathochromic effect) in absorption pattern attributed to band gap energy (Eg) decreases. Photoluminescence spectra examined the recombination rate of electrons (e-) and holes (h+) as charge carriers. A sufficient catalytic activity (CA) was observed against methylene blue (MB) dye in an acidic medium (99.74%) and efficient bactericidal action was studied against (E. coli) with zone of inhibition (5.20 mm) for 4% Y-doped MoO3. In addition, in silico docking demonstrated potential inhibitory effect of produced nanomaterials on FabH and FabI enzymes of fatty acid biosynthesis.


Subject(s)
Escherichia coli , Nanotubes , Molecular Docking Simulation , Anti-Bacterial Agents/pharmacology
7.
Int J Biol Macromol ; 251: 126343, 2023 Aug 14.
Article in English | MEDLINE | ID: mdl-37586627

ABSTRACT

Manganese dioxide (MnO2) nanorods and (3, 6, and 9 mL) chitosan grafted polyacrylic acid (CS-g-PAA) doped MnO2 were prepared hydrothermally. The study objective is to decrease the recombination rate of MnO2 upon doping to enhance the dye degradation efficiency and antimicrobial activity. The doping-dependent properties of CS-g-PAA on phase identification, functional groups, optical characteristics, elemental compositions, and morphological analyses of MnO2 nanorods were conducted using systematic characterization techniques. XRD pattern shows that MnO2 has a tetragonal structure, with increased crystallite size (15.87 to 29.36 nm) upon doping. The TEM analysis showed that MnO2 has nanorods and that CS-g-PAA doped MnO2 displayed nanoflakes-like structures. The decrease in electron-hole pair recombination rate on doping was verified by PL spectroscopy, demonstrating the enhanced catalytic activity. Moreover, adding grafted binary polymers to MnO2 inhibits bacterial cell growth by binding with the negatively charged cell wall and preventing biofilm formation. The 9 mL doped sample displayed a maximum degradation (99.27 %) in a neutral medium and 85.84 % antimicrobial efficiency against E. coli. The enoyl-acyl carrier protein reductase (FabIE. coli) and DNA gyrase(E. coli) were inhibited by these CS-g-PAA doped MnO2 nanostructures (NSs), as shown by in silico molecular docking studies.

8.
ACS Omega ; 8(28): 25401-25409, 2023 Jul 18.
Article in English | MEDLINE | ID: mdl-37483192

ABSTRACT

This work demonstrates the degradation of toxic RhB (rhodamine B) dye from polluted water in various pH environments. It assesses the antibacterial action of CDs (carbon dots)/CS (chitosan)-doped La2O3 (lanthanum oxide) NRs (nanorods). CS and CDs have been introduced as dopants to modify the characteristics of La2O3 to achieve efficient outcomes. The influence of doping on the structural, morphological, optical, and elemental properties of synthesized La2O3 NRs was investigated through a number of analytical techniques. The structural analysis of XRD revealed a hexagonal phase. The rod-like structure of pure La2O3 and reduction in the size of NRs upon doping were exhibited by TEM micrographs. From UV-vis spectroscopy, increased absorption upon doping and introduction of redshift that led to reduced bandgap energy were observed. The FTIR spectra indicate the presence of functional groups of pure and integrated samples. The catalytic activity of specimens in basic medium toward dye showed excellent results (94.57%). The inhibition zone of diameter 4.15 mm was evaluated by 6 mL of CDs/CS-doped La2O3 NRs against Escherichia coli once the surface area increased by dopants. In silico experiments were performed for enoyl-[acyl-carrier-protein] reductase (FabI) and DNA gyrase enzymes to assess the potency of CS-doped La2O3 and CDs/CS-doped La2O3 as their inhibitors and to justify their possible mechanism of action.

9.
ACS Appl Mater Interfaces ; 11(33): 30185-30196, 2019 Aug 21.
Article in English | MEDLINE | ID: mdl-31347822

ABSTRACT

To overcome the critical limitations of liquid-electrolyte-based dye-sensitized solar cells, quasi-solid-state electrolytes have been explored as a means of addressing long-term device stability, albeit with comparatively low ionic conductivities and device performances. Although metal oxide additives have been shown to augment ionic conductivity, their propensity to aggregate into large crystalline particles upon high-heat annealing hinders their full potential in quasi-solid-state electrolytes. In this work, sonochemical processing has been successfully applied to generate fine Co3O4 nanoparticles that are highly dispersible in a PAN:P(VP-co-VAc) polymer-blended gel electrolyte, even after calcination. An optimized nanocomposite gel polymer electrolyte containing 3 wt % sonicated Co3O4 nanoparticles (PVVA-3) delivers the highest ionic conductivity (4.62 × 10-3 S cm-1) of the series. This property is accompanied by a 51% enhancement in the apparent diffusion coefficient of triiodide versus both unmodified and unsonicated electrolyte samples. The dye-sensitized solar cell based on PVVA-3 displays a power conversion efficiency of 6.46% under AM1.5 G, 100 mW cm-2. By identifying the optimal loading of sonochemically processed nanoparticles, we are able to generate a homogenous extended particle network that effectively mobilizes redox-active species through a highly amorphous host matrix. This effect is manifested in a selective 51% enhancement in photocurrent density (JSC = 16.2 mA cm-2) and a lowered barrier to N719 dye regeneration (RCT = 193 Ω) versus an unmodified solar cell. To the best of our knowledge, this work represents the highest known efficiency to date for dye-sensitized solar cells based on a sonicated Co3O4-modified gel polymer electrolyte. Sonochemical processing, when applied in this manner, has the potential to make meaningful contributions toward the ongoing mission to achieve the widespread exploitation of stable and low-cost dye-sensitized solar cells.

10.
J Am Chem Soc ; 138(7): 2292-301, 2016 Feb 24.
Article in English | MEDLINE | ID: mdl-26812983

ABSTRACT

Porous metal-organic frameworks (MOFs) have been studied in the context of a wide variety of applications, particularly in relation to molecular storage and separation sciences. Recently, we reported a green, renewable framework material composed of γ-cyclodextrin (γ-CD) and alkali metal salts--namely, CD-MOF. This porous material has been shown to facilitate the separation of mixtures of alkylaromatic compounds, including the BTEX mixture (benzene, toluene, ethylbenzene, and the regioisomers of xylene), into their pure components, in both the liquid and gas phases, in an energy-efficient manner which could have implications for the petrochemical industry. Here, we report the ability of CD-MOF to separate a wide variety of mixtures, including ethylbenzene from styrene, haloaromatics, terpinenes, pinenes and other chiral compounds. CD-MOF retains saturated compounds to a greater extent than their unsaturated analogues. Also, the location of a double bond within a molecule influences its retention within the extended framework, as revealed in the case of the structural isomers of pinene and terpinine, where the isomers with exocyclic double bonds are more highly retained than those with endocyclic double bonds. The ability of CD-MOF to separate various mono- and disubstituted haloaromatic compounds appears to be controlled by both the size of the halogen substituents and the strength of the noncovalent bonding interactions between the analyte and the framework, an observation which has been confirmed by molecular simulations. Since CD-MOF is a homochiral framework, it is also able to resolve the enantiomers of chiral analytes, including those of limonene and 1-phenylethanol. These findings could lead to cheaper and easier-to-prepare stationary phases for HPLC separations when compared with other chiral stationary phases, such as CD-bonded silica particles.

11.
Org Lett ; 17(9): 2146-9, 2015 May 01.
Article in English | MEDLINE | ID: mdl-25894019

ABSTRACT

A versatile surface-functionalization strategy applicable to mesoporous silica nanoparticles, which could potentially serve as drug delivery vehicles, is described that makes use of alkoxyamine tethers on the surface of the nanoparticles. A wide variety of carbonyl compounds can be attached readily to these tethers under the mild conditions of oxime ether formation, simply by incubating the chemically modified mesoporous silica nanoparticles with aldehydes or ketones in water.


Subject(s)
Nanoparticles/chemistry , Silicon Dioxide/chemistry , Drug Delivery Systems , Ligation , Molecular Structure , Oximes/chemistry
12.
Nanoscale ; 7(16): 7178-83, 2015 Apr 28.
Article in English | MEDLINE | ID: mdl-25820516

ABSTRACT

Gating of mesoporous silica nanoparticles (MSNs) with the stimuli-responsive poly(ß-amino ester) has been achieved. This hybrid nanocarrier releases doxorubicin (DOX) under acidic conditions or in the presence of porcine liver esterase. The DOX loaded poly(ß-amino ester)-capped MSNs reduce cell viability when tested on MDA-MB-231 human breast cancer cells.


Subject(s)
Drug Carriers/chemistry , Esterases/metabolism , Nanoparticles/chemistry , Polymers/chemistry , Silicon Dioxide/chemistry , Animals , Antibiotics, Antineoplastic/chemistry , Antibiotics, Antineoplastic/toxicity , Cell Line, Tumor , Cell Survival/drug effects , Doxorubicin/chemistry , Doxorubicin/toxicity , Esterases/chemistry , Humans , Hydrogen-Ion Concentration , Porosity , Swine
14.
J Am Chem Soc ; 137(17): 5706-19, 2015 May 06.
Article in English | MEDLINE | ID: mdl-25806952

ABSTRACT

Metal-organic frameworks (MOFs) are known to facilitate energy-efficient separations of important industrial chemical feedstocks. Here, we report how a class of green MOFs-namely CD-MOFs-exhibits high shape selectivity toward aromatic hydrocarbons. CD-MOFs, which consist of an extended porous network of γ-cyclodextrins (γ-CDs) and alkali metal cations, can separate a wide range of benzenoid compounds as a result of their relative orientation and packing within the transverse channels formed from linking (γ-CD)6 body-centered cuboids in three dimensions. Adsorption isotherms and liquid-phase chromatographic measurements indicate a retention order of ortho- > meta- > para-xylene. The persistence of this regioselectivity is also observed during the liquid-phase chromatography of the ethyltoluene and cymene regioisomers. In addition, molecular shape-sorting within CD-MOFs facilitates the separation of the industrially relevant BTEX (benzene, toluene, ethylbenzene, and xylene isomers) mixture. The high resolution and large separation factors exhibited by CD-MOFs for benzene and these alkylaromatics provide an efficient, reliable, and green alternative to current isolation protocols. Furthermore, the isolation of the regioisomers of (i) ethyltoluene and (ii) cymene, together with the purification of (iii) cumene from its major impurities (benzene, n-propylbenzene, and diisopropylbenzene) highlight the specificity of the shape selectivity exhibited by CD-MOFs. Grand canonical Monte Carlo simulations and single component static vapor adsorption isotherms and kinetics reveal the origin of the shape selectivity and provide insight into the capability of CD-MOFs to serve as versatile separation platforms derived from renewable sources.

15.
ACS Nano ; 9(2): 1461-70, 2015 Feb 24.
Article in English | MEDLINE | ID: mdl-25555133

ABSTRACT

Polyaromatic compounds are well-known to intercalate DNA. Numerous anticancer chemotherapeutics have been developed upon the basis of this recognition motif. The compounds have been designed such that they interfere with the role of the topoisomerases, which control the topology of DNA during the cell-division cycle. Although many promising chemotherapeutics have been developed upon the basis of polyaromatic DNA intercalating systems, these candidates did not proceed past clinical trials on account of their dose-limiting toxicity. Herein, we discuss an alternative, water-soluble class of polyaromatic compounds, the 2,9-diazaperopyrenium dications, and report in vitro cell studies for a library of these dications. These investigations reveal that a number of 2,9-diazaperopyrenium dications show similar activities as doxorubicin toward a variety of cancer cell lines. Additionally, we report the solid-state structures of these dications, and we relate their tendency to aggregate in solution to their toxicity profiles. The addition of bulky substituents to these polyaromatic dications decreases their tendency to aggregate in solution. The derivative substituted with 2,6-diisopropylphenyl groups proved to be the most cytotoxic against the majority of the cell lines tested. In the solid state, the 2,6-diisopropylphenyl-functionalized derivative does not undergo π···π stacking, while in aqueous solution, dynamic light scattering reveals that this derivative forms very small (50-100 nm) aggregates, in contrast with the larger ones formed by dications with less bulky substituents. Alteration of the aromaticitiy in the terminal heterocycles of selected dications reveals a drastic change in the toxicity of these polyaromatic species toward specific cell lines.


Subject(s)
Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Aza Compounds/chemistry , Aza Compounds/pharmacology , Cell Line, Tumor , Humans , Inhibitory Concentration 50 , Models, Molecular , Molecular Conformation , Solubility , Water/chemistry
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