Kumari Smita

Sonochemical Synthesis of Silver Nanoparticles Using Starch: A Comparison

A novel approach was applied to synthesize silver nanoparticles using starch under sonication. Colloidal silver nanoparticles solution exhibited an increase of absorption from 420 to 440 nm with increase starch quantity. Transmission electron microscopy followed by selected area electron diffraction pattern analysis indicated the formation of spherical, polydispersed, amorphous, silver nanoparticles of diameter ranging from 23 to 97 nm with mean particle size of 45.6 nm. Selected area electron diffraction (SAED) confirmed partial crystalline and amorphous nature of silver nanoparticles. Silver nanoparticles synthesized in this manner can be used for synthesis of 2-aryl substituted benzimidazoles which have numerous biomedical applications. The optimized reaction conditions include 10 ml of 1 mM AgNO3, 25 mg starch, 11 pH range, and sonication for 20 min at room temperature.

Green synthesis of silver nanoparticles using Andean blackberry fruit extract

Green synthesis of nanoparticles using various plant materials opens a new scope for the phytochemist and discourages the use of toxic chemicals. In this article, we report an eco-friendly and low-cost method for the synthesis of silver nanoparticles (AgNPs) using Andean blackberry fruit extracts as both a reducing and capping agent. The green synthesized AgNPs were characterized by various analytical instruments like UV–visible, transmission electron microscopy (TEM), dynamic light scattering (DLS), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. The formation of AgNPs was analyzed by UV–vis spectroscopy at λmax = 435 nm. TEM analysis of AgNPs showed the formation of a crystalline, spherical shape and 12–50 nm size, whereas XRD peaks at 38.04°, 44.06°, 64.34° and 77.17° confirmed the crystalline nature of AgNPs. FTIR analysis was done to identify the functional groups responsible for the synthesis of the AgNPs. Furthermore, it was found that the AgNPs showed good antioxidant efficacy (>78%, 0.1 mM) against 1,1-diphenyl-2-picrylhydrazyl. The process of synthesis is environmentally compatible and the synthesized AgNPs could be a promising candidate for many biomedical applications.

One pot phytosynthesis of gold nanoparticles using Genipa americana fruit extract and its biological applications.

In this article, rapid one pot synthesis of gold nanoparticles (GNPs) using an eco-friendly extract of Genipa americana L. fruit is described. Electrospray ionization mass spectrometry (ESI-MS) and Fourier transform infrared (FTIR) spectroscopic studies demonstrated that small molecules such as genipin, genipaol, geniposide and ranolazine can act as reducer as well as stabilizers. The monodispersed, spherical GNPs were further characterized by UV-vis spectroscopy at λmax=535 nm, transmission electron microscopy (TEM), dynamic light scattering (DLS) and X-ray diffraction (XRD) analysis. This synthetic approach offers a greener and alternate route to the preparation of GNPs free from toxic chemical components and stable for 6-7 months under room temperature. The green synthesized GNPs showed weak antioxidant efficacy against 1,1-diphenyl-2-picrylhydrazyl and no cytotoxicity against A-549 and HeLa human cancer cell lines, from lung and cervix. This study opens a new industrial scope of G. americana fruit in nanoscience and as surface modified GNPs can be developed into a successful drug carrier for future pharmaceutical products.

Green Approach for Fabrication and Applications of Zinc Oxide Nanoparticles

Zinc oxide nanoparticles (ZnO-NPs) are known to be one of the multifunctional inorganic compounds which are widely used in everyday applications. This study aims to fabricate ZnO-NPs using grapefruit (Citrus paradisi) peel extract with particle size ranging from 12 to 72 nm. Structural, morphological, and optical properties of the synthesized nanoparticles have been characterized by using UV-Vis spectrophotometer, TEM, DLS, and FTIR analysis. They show the significant photocatalytic degradation efficiency (>56%, 10 mg/L, 6 h) against methylene blue and antioxidant efficacy (≥80% for 1.2 mM) against 1,1-diphenyl-2-picrylhydrazyl. From the results obtained it is suggested that green ZnO-NPs could be used effectively in environmental safety applications and also can address future medical concerns.

In vitro evaluation of silver nanoparticles cytotoxicity on Hepatic cancer (Hep-G2) cell line and their antioxidant activity: Green approach for fabrication and application.

In this article, biosynthesis of silver nanoparticles (AgNPs) using Andean Mora (Rubus glaucus Benth.) leaf has been reported. Different analytical techniques including UV-vis spectroscopy, dynamic light scattering (DLS), transmission electron microscopy (TEM) and X-ray diffraction (XRD) were used for the characterization of AgNPs. The initial appearance of color change with the intense surface plasmon resonance (SPR) bands around 440-455 in UV-visible spectra revealing the formation of AgNPs. The TEM image showed the AgNPs to be anisotropic, quasi-spherical in shape with sizes in the range of 12-50nm. On the other hand, XRD studies revealed the formation of face-centered cubic structure for AgNPs. The surface modified AgNPs showed no cytotoxicity at the concentration ranging from 0.01μM to 1.0μM on the Hepatic cancer (Hep-G2) cell line and observed antioxidant efficacy >70% at the concentration 0.05mM/0.20mL against 1, 1-diphenyl-2-picrylhydrazyl. From the results obtained it is suggested that AgNPs could be used effectively in future drug delivery systems and other biomedical concerns.

Biofabrication of nanogold from the flower extracts of Lantana camara.

The present investigation was done to explore the potential of Lantana camara (L. camara) flower in the fabrication of gold nanoparticles (AuNPs). The shape and size of AuNPs have been successfully controlled by introducing small amounts of L. camara flower extract. It produced spherical nanogold of average size 10.6 ± 2.9 nm without any aggregation and showed significant photocatalytic degradation activity of the methylene blue (>62%, 10 mg/L) in the presence of solar light. In addition, the experimental approach is inexpensive, rapid and eco-friendly for industrial scale production of nanoparticles.

Aqueous Phase Lavender Leaf Mediated Green Synthesis of Gold Nanoparticles and Evaluation of its Antioxidant Activity

In this paper, green synthesis of gold nanoparticles (AuNPs) using leaf extract of Lavender (Lavandula angustifolia) and their antioxidant activity was evaluated under the ambient aqueous phase condition. Assynthesized AuNPs were characterized by visual, ultraviolet–visible–near infrared (UV–vis–NIR) spectroscopy, transmission electron microscopy (TEM), and dynamic light scattering (DLS) technique. Formation of AuNPs produces an intense absorbance peak at 530 and 1055 nm in UV–visible spectroscopy. TEM and DLS results confirmed that the synthesized AuNPs were crystalline, polydisperse, quasi-spherical and triangular shape with an average size ranging from 34–300 nm. UV-vis-NIR, TEM, and DLS study showed that the phytochemicals from the Lavender leaf extract have dual properties of reducing and stabilizing agents. Further, AuNPs (21.53%, 0.2 mL) showed higher antioxidant activity than Lavender leaf extract (4.73%, 0.2 mL) against 2,2-diphenyl-1-picrylhydrazyl. On looking these advantages, green synthesis of AuNPs without inert atmosphere is highly recommended for future medicinal and industrial application.

Extracellular green synthesis of silver nanoparticles using Amazonian fruit Araza (Eugenia stipitata McVaugh)

Abstract An eco-friendly method for the extracellular synthesis of silver nanoparticles (AgNPs) using aqueous Araza fruit extract and their antioxidant activity was investigated. It was observed that UV–Vis absorption peak is dependent on various parameters such as pH, temperature, and change of time. The initial appearance of the yellow color with intense surface plasmon bands at 430–450 nm, then transmission electron microscopy, scanning electron microscopy and X-ray diffraction analysis revealed the formation of 15–45 nm sized, spherical and crystalline AgNPs. Fourier transform infrared spectroscopy depicted that malic acid, citric acid, and carotenoids of Araza fruit involved in the synthesis of AgNPs. In addition, the surface modified AgNPs (77.42%, 1 mL) showed nearly double antioxidant efficiency than Araza fruit extract (35.30%, 1 mL) against 1, 1-diphenyl-2-picrylhydrazyl. The present study highlights the possibility of using the Araza fruit to synthesize AgNPs, which could be used effectively in the present and future antioxidant agent.

Phytosynthesis of gold nanoparticles using Andean Ajı′ (Capsicum baccatum L.)

Abstract This article covers the importance of Andean Ajı′/Chilli (Capsicum baccatum L.) mediated synthesis of gold nanoparticles (AuNPs), which favors for green chemistry and escape us from the use of hazardous chemicals. UV–visible spectroscopy was used to monitor the quantitative formation of AuNPs. Further, as synthesized AuNPs were characterized using Transmission electron microscopy, Dynamic Light Scattering, and X-ray diffraction. It produced spherical AuNPs at λmax = 540 nm of average size 23.9 ± 9.7 nm without any aggregation. Ajı′ extract (aq) was the good reducing and capping agent in terms of conversion to Au3+ to AuNPs. The synthesized AuNPs, also enhancing the photocatalytic degradation of methylene blue (>50%, k = 1.9585 × 10−3 min−1) under direct solar light irradiation. In addition, the experimental approach is benign, ecofriendly, and inexpensive for industrial-scale production of nanoparticles using Aji extract as natural bioreductant.

Ionic Liquid Based Silica Tuned Silver Nanoparticles: Novel Approach for Fabrication

A novel synthetic method for the fabrication of silver nanoparticles has been developed in the presence silica functionalized ionic liquids. The synthesized AgNPs are with particle size ranging from 25 to 50 nm and further characterized by UV-vis spectroscopy, dynamic light scattering, transmission electron microscopy, and Fourier transform infrared spectroscopy. Selected area electron diffraction confirmed the formation of metallic Ag. The method provides several advantages such as green solvent, shorter reaction time and could be used effectively in future engineering or medical concerns.