Search

In the present study, we report a simple and ecofriendly phytosynthesis of silver nanoparticles (AgNPs) using fruits of Capsicum baccatum L. (Andean chili). During the reaction, the phytoconstituents of C. baccatum act as a reducing and stabilizing agent. Phyotsynthesized AgNPs were characterized through various spectroscopy and microscopic techniques. The produced AgNPs showed a plasmon band at λmax = 458 nm and stable for 10 days, confirmed by UV-vis spectroscopy. Transmission electron microscopy (TEM) explained that the produced AgNPs were quasi-spherical in shape with an average size of 10–30 nm and small aggregation. The X-ray diffraction analysis confirmed the crystalline nature of the AgNPs. Aggregation of AgNPs was indicated in the dynamic light scattering (DLS) and TEM analysis. AgNPs also exhibited quenching/sensing activity of H2O2 (>50%) at room temperature. The results demonstrate that as-synthesized AgNPs are inexpensive, sustainable and could be an alternative as optical chemical sensors. [ABSTRACT FROM AUTHOR]

Abstract In this work, we describe a simplified and bottom-up synthesis of silver nanoparticles (AgNPs) using pollen collected by Andean honeybees as a natural reducing and capping agent for the first time. The biosynthesized AgNPs were characterized by their optical properties, electrochemical properties, average size, morphology, and purity by various analytical techniques. The synthesized AgNPs were spherical, having 10–35 nm size, showed λmax at 440 nm, well dispersed, and remained stable for up to 1 month under laboratory conditions without any sedimentation. Moreover, we also investigated the usability of synthesized AgNPs as antioxidants against 1, 1-diphenyl-2-picrylhydrazyl (DPPH). Thus, this protocol may be adapted for the large-scale production of nanoparticles without the use of chemical solvents and supports the importance of local resources in green chemistry. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM PUBLISHER]

The challenge of extraction of natural product in the twenty-first century is to achieve 100% selectivity of the desired product and develop renewable energy based processes. An object of the present work is to provide a method for producing specific bioactive compounds from agricultural products. A simple protocol was used to obtain the conditions of microwave-assisted extraction (MWAE) and ultrasound-assisted extraction (USAE). Total quercetin content under microwave irradiation for 150 sec at pH 6.25 (209 mg/ 100 gm F. wt). The effects of operating conditions, such as extraction time and pH on the extraction yield of quercetin were studied. Microwave-assisted ionic liquid-based silica sorbent (ILSis) was developed by a process involving surface chemical modification of commercial silica using a synthesized ionic liquid and characterized by FTIR. The obtained particles were successfully used as a special sorbent in a solid-phase separation process to isolate quercetin and its glycosides from solid onion. Different washing and elution solvents, such as water, water/methanol (v/v), and pure methanol were evaluated. Ionic liquid-based silica sorbent was compared with traditional C18 sorbent and it exhibited higher selectivity. The target compounds in solid onion containing quercetin and its glycosides were determined. [ABSTRACT FROM AUTHOR]

This article covers the importance of Andean Ajı′/Chilli (Capsicum baccatumL.) 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 atλmax = 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. [ABSTRACT FROM AUTHOR]