The food packaging industry explores economically viable, environmentally benign, and non-toxic packaging materials. Biopolymers, including chitosan (CH) and gelatin (GE), are considered a leading ...replacement for plastic packaging materials, with preferred packaging functionality and biodegradability. CH, GE, and different proportions of silver nanoparticles (AgNPs) are used to prepare novel packaging materials using a simple solution casting method. The functional and morphological characterization of the prepared films was carried out by using Fourier transform infrared spectroscopy (FTIR), UV–Visible spectroscopy, and scanning electron microscopy (SEM). The mechanical strength, solubility, water vapor transmission rate, swelling behavior, moisture retention capability, and biodegradability of composite films were evaluated. The addition of AgNPs to the polymer blend matrix improves the physicochemical and biological functioning of the matrix. Due to the cross-linking motion of AgNPs, it is found that the swelling degree, moisture retention capability, and water vapor transmission rate slightly decrease. The tensile strength of pure CH–GE films was 24.4 ± 0.03, and it increased to 25.8 ± 0.05 MPa upon the addition of 0.0075% of AgNPs. The real-time application of the films was tested by evaluating the shelf-life existence of carrot pieces covered with the composite films. The composite film containing AgNPs becomes effective in lowering bacterial contamination while comparing the plastic polyethylene films. In principle, the synthesized composite films possessed all the ideal characteristics of packaging material and were considered biodegradable and biocompatible food packaging material and an alternate option for petroleum-based plastics.
Silver nanoparticles have been synthesized using green and chemical methods.
Mussaenda frondosa
(
M. frondosa
) leaf extract and sodium citrate used as reducing and stabilizing agents for the ...synthesis of silver nanoparticles (AgNPs) in green and chemical methods. The synthesized nanoparticles were characterized using UV-vis spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), thermal gravimetric analysis (TGA), and transmission electron microscopy (TEM). The antioxidant activity of green and chemically synthesized nanoparticles was evaluated by DPPH (1, 1-Diphenyl-2-picrylhydrazyl) assay and observed that green synthesized nanoparticles possess remarkable antioxidant activity compared to chemically synthesized nanoparticles and it can be used for enormous applications in the biomedical field. The present study enlightens the importance of green synthesized AgNPs using
M. frondosa
leaf extract over the chemically synthesized one.
A facile green synthetic method is proposed for the synthesis of zinc oxide nanoparticles (ZnO NPs) using the bio-template Cinnamomum tamala (C. tamala) leaves extract. The morphological, functional, ...and structural characterization of synthesized ZnO NPs were studied by adopting different techniques such as energy dispersive X-ray analysis (EDX), high-resolution transmission electron microscopy (HR-TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), UV-Visible spectroscopy, fourier transform infrared (FTIR) spectroscopy, raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). The fabricated ZnO NPs exhibit an average size of 35 nm, with a hexagonal nanostructure. Further, the well-characterized ZnO NPs were employed for the photocatalytic degradation of methylene blue (MB) in an aqueous solution. The photocatalytic activity was analyzed by changing the various physicochemical factors such as reaction time, amount of photocatalyst, precursor concentration, and calcination temperature of the ZnO NPs. All the studies suggest that the ZnO synthesized through the green protocol exhibits excellent photocatalytic potency against the dye molecules.
The present study reports a green and sustainable method for the synthesis of titanium dioxide (TiO₂) nanoparticles (NPs) from titanium oxysulfate solution using Kondagogu gum (
), a carbohydrate ...polymer, as the NPs formation agent. The synthesized TiO₂ NPs were categorized by techniques such as X-Ray Diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy analysis, Raman spectroscopy, scanning electron microscope- Energy-dispersive X-ray spectroscopy (SEM-EDX), Transmission electron microscopy (TEM), High-resolution transmission electron microscopy (HR-TEM), UV-visible spectroscopy, Brunauer-Emmett-Teller (BET) surface area and particle size analysis. Additionally, the photocatalytic actions of TiO₂ NPs were assessed with regard to their ability to degrade an organic dye (methylene blue) from aqueous solution in the presence of solar light. Various parameters affecting the photocatalytic activity of the TiO₂ NPs were examined, including catalyst loading, reaction time, pH value and calcination temperature of the aforementioned particles. This green synthesis method involving TiO₂ NPs explores the advantages of inexpensive and non-toxic precursors, the TiO₂ NPs themselves exhibiting excellent photocatalytic activity against dye molecules.
Green bionanocomposites have garnered considerable attention and applications in the pharmaceutical and packaging industries because of their intrinsic features, such as biocompatibility and ...biodegradability. The work presents a novel approach towards the combined effect of glycerol, tween 80 and silver nanoparticles (AgNPs) on the physicochemical properties of lyophilized chitosan (CH) scaffolds produced via a green synthesis method.The produced bionanocomposites were characterized with the help of Fourier transform infrared spectroscopy (FTIR) and Scanning electron microscopy (SEM). The swelling behavior, water vapor transmission rate, moisture retention capability, degradation in Hanks solution, biodegradability in soil, mechanical strength and electrochemical performance of the composites were evaluated. The addition of additives to the CH matrix alters the physicochemical and biological functioning of the matrix. Plasticized scaffolds showed an increase in swelling degree, water vapor transmission rate and degradability in Hank's balanced solution compared to the blank chitosan scaffolds. The addition of tween 80 made the scaffolds more porous, and changes in physicochemical properties were observed. Green-synthesized AgNPs showed intensified antioxidant and antibacterial properties. Incorporating biogenic nanoparticles into the CH matrix enhances the polymer composites' biochemical properties and increases the demand in the medical and biological sectors. These freeze-dried chitosan-AgNPs composite scaffolds had tremendous applications, especially in biomedical fields like wound dressing, tissue engineering, bone regeneration, etc.
In the current study, we utilize leaves of
Aerva lanata
as the precursor to produce carbon dots (CDs) adopting a one-step hydrothermal approach without the use of extra chemical reagents or surface ...modification. They have hydroxyl and carboxyl groups as surface functionalities, were well soluble in water, were biocompatible, and exhibited bright fluorescence. The applications of the prepared CDs in three broad areas were carefully described. As a fluorescence-based sensor, the prepared sensor was able to sense ciprofloxacin. Ciprofloxacin enhanced the fluorescent intensity of CDs, and a linear correlation between the intensity of fluorescence and the concentration of ciprofloxacin in a wide range with an LOD of 0.4 nM was observed. The mechanism behind the fluorescence enhancement seen with the addition of ciprofloxacin was revealed to be charge transfer and hydrogen bonding. As an electrochemical probe, a carbon dot-modified glassy carbon electrode was able to sense copper ions with good selectivity and an LOD of 4 nM. Cu(II) electrochemical sensing was comprehensively examined, with a complete description of the electron transport process. The anticounterfeiting properties of the synthesized CDs were also proven. The successful real sample analysis also paved the way for an environment-friendly sensor for exhibiting its potential for multifaceted applications. This study not only introduced a new carbon dot to improve our understanding of material properties but also delved into all of its possible applications.
Graphical abstract
An economical and easy one-step method for the biosynthesis of highly stable molybdenum trioxide (MoO
3
) nanoparticles was developed using gum arabic as a bio-template; ensuing nanoparticles (NP) ...were characterized by X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, Raman spectroscopy, UV–visible spectroscopy, transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDX). The crystallinity and purity of MoO
3
nanoparticles in the orthorhombic phase were confirmed by XRD analysis, and their rod-shaped identity (average sizes ranging from 7.5 to 42 nm) were observed by TEM. Cytotoxic effects of the NP were monitored using Hep G2 (human liver cancer) and HEK 293 (human embryonic kidney) cell lines via 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide assays. The results of this study revealed that MoO
3
nanoparticles are nontoxic towards Hep G2 cell lines and displayed negligible toxicity, even at very high concentrations (1000 ppm), although had moderate toxicity towards HEK 293 cells. Furthermore, their catalytic activity was evaluated for the reduction of
p
-nitrophenol to
p
-aminophenol.
Graphical abstract
Synopsis: Green synthesis of MoO
3
nanorods using gum arabic demonstrated as an eco-friendly catalyst for the conversion of
p
-nitrophenol with negligible toxicity towards Hep
G
2 cell lines.
The plant mediated biogenic synthesis of nanoparticles is of magnificent concern due to its eco-benign and single pot nature. Here,
(
) aqueous leaf extract was utilised for the silver nanoparticles’ ...(Ag NPs) synthesis. The phytoconstituents in the leaf extract were analysed by standard methods. These metabolites, especially carbohydrate polymers reduce Ag ions to Ag NPs accompanied by a reddish-brown coloration of the reaction mixture. The visual observation of intense brown colour is the first indication of the formation of Ag NPs. Various spectro-analytical techniques further characterise the Ag NPs. The green synthesised spherical Ag NPs were crystalline with an average size of 38 nm. The Ag NPs were scrutinised for antioxidant, antimicrobial and cytotoxic activity and obtained good results. The free radical scavenging was studied by 2, 2-Diphenyl-l-picrylhydrazyl (DPPH) assay. The antibacterial activity of Ag NPs was assessed against human pathogens, and it shown to have good antibacterial potency against a wide spectrum of bacteria. The cytotoxic activity against HEK-293T (human embryonic kidney) cell line was evaluated by 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) assay. These potent biological activities enable
capped Ag NPs to be suitable candidates for the future applications in various fields, predominantly clinical and biomedical.
A novel greener methodology is reported for the synthesis of titanium dioxide (TiO2) nanoparticles (NPs) using gum Arabic (Acacia senegal) and the characterization of the ensuing TiO2 NPs by various ...techniques such as X-ray diffraction (XRD), Fourier transform infrared, Raman spectroscopy, scanning electron microscopy–energy dispersive X-ray, transmission electron microscopy (TEM), high resolution-TEM, and UV–visible spectroscopy. The XRD analysis confirmed the formation of TiO2 NPs in the anatase phase with high crystal purity, while TEM confirmed the size to be 8.9 ± 1.5 nm with a spherical morphology. The electrode for the electrochemical detection of Pb2+ ions was modified by a carbon paste fabricated using the synthesized TiO2 NPs. Compared to the bare electrode, the fabricated electrode exhibited improved electro–catalytic activity toward the reduction of Pb2+ ions. The detection limit, quantification limit, and the sensitivity of the developed electrode were observed by using differential pulse voltammetry to be 506 ppb, 1.68 ppm, and 0.52 ± 0.01 μA μM–1, respectively. The constructed electrode was tested for the detection of lead content in plastic toys.
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•The synthesis of highly fluorescent CDs using Alternanthera sessilis leaves as the precursor is reported for the first time.•The fabricated CDs act as highly sensitive and selective ...sensors for the fluorescent and electrochemical detection of Cu2+ and Zn2+ ions respectively..•The detection limits of the suggested sensors were of nanomolar range.•The synthesized CDs exhibited high anticancer and antimicrobial potentials.
Herein, the green synthesis of novel fluorescent carbon dots (CDs) from the Alternanthera sessilis plant by a simple, eco-friendly, and facile hydrothermal method was reported. The developed CDs exhibit green fluorescence and have a size of 5.25 nm. Various analyses reveal outstanding features, including high quantum yield, good photostability, and excellent hydrophilicity of the as-synthesized CDs. It was used as a dual-mode probe for the sensing of Cu2+ ions and Zn2+ ions in an aqueous system. Efficient sensing of Cu2+ ions takes place by static quenching of fluorescence with a detection limit of 28.03 nM. CDs-coated glassy carbon electrode was used to perform the electrochemical detection of Zn2+ ions in an aqueous system with high selectivity and sensitivity, and the LOD value was found to be 2.28 nM. The LC50 value of the fabricated CDs against the human breast cancer cell line is 89.85 µL/mL. Also, the antimicrobial efficacy of the CDs was examined against Escherichia coli, Staphylococcus Aureus, and Aspergillus niger, and the results indicate the high toxicity of the CDs against all tested microbial strains.
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