Biogenic synthesis of silver nanoparticles (AgNP) was performed at room temperature using Aloe vera plant extract in the presence of ammoniacal silver nitrate as a metal salt precursor. The formation of AgNP was monitored by UV-visible spectroscopy at different time intervals. The shape and size of the synthesized particle were visualized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations. These results were confirmed by X-ray powder diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) analyses and further supported by surface-enhanced Raman spectroscopy/Raman scattering (SERS) study. UV-visible spectrum has shown a sharp peak at 420 nm and further evidenced by FTIR peak profile (at 1587.6, 1386.4, and 1076 cm−1 with corresponding compounds). The main band position with SERS was noticed at 1594 cm−1 (C–C stretching vibration). When samples were heated under microwave radiation, AgNP with octahedron shapes with 5–50 nm were found and this method can be one of the easier ways to synthesis anisotropic AgNP, in which the plant extract plays a vital role to regulate the size and shape of the nanoparticles. Enhanced antibacterial effects (two- to fourfold) were observed in the case of Aloe vera plant protected AgNP than the routinely synthesized antibiotic drugs.Graphical AbstractShape and size-controlled synthesis of silver nanoparticles using Aloe vera plant extract Electronic supplementary materialThe online version of this article (doi:10.1186/s11671-016-1725-x) contains supplementary material, which is available to authorized users.

A biosynthesis of Copper Nanoparticles supported on Zeolite Y and its application as efficient, reusable, heterogeneous catalyst in C−N cross coupling reactions between amines and aryl halides are reported. The biosynthesis of CuNPs/Zeolite Y was achieved by the reduction of CuSO4.5H2O with the lemon juice (without peal) and encapsulated into the Zeolite Y in a single step. In this biosynthetic method, the ascorbic acid present in the lemon juice acted as a reducing agent for CuSO4.5H2O. The CuNPs/Zeolite Y was characterized using UV‐Vis, powder XRD, FT‐IR, HR SEM, EDS and TGA. The average size of the CuNPs are found to be 50 nm and has large surface area for the efficient catalysis. The new catalyst is effect in catalyzing the C−N cross coupling reaction between amines and aryl halides (yield ranging from 89% to 95% depends on amine and aryl halide used). The catalyst can be recovered from the reaction mixture by simple procedure. The recovered catalyst is found to be active in catalyzing the coupling reaction even after five runs.

We demonstrate a green chemistry approach to synthesize narrow-sized zerovalent iron (nZVI) nanoparticles using Artocarpus heterophyllus Lam. leaf extract as reducing and capping agent. The produced nZVI was characterized by various instrumental methods including ultraviolet-visible spectra, transmission electron microscopy, vibrating sample magnetometer (VSM), X-ray diffraction, and Fourier transform infrared spectroscopy. Based on the electron microscopy observations, the particle size was estimated to be ∼30 nm. In VSM, the saturation point of magnetization was observed to be 0.6 emu g −1 under a magnetic field of 0 ± 30 kOe. The synthesized nZVI was amorphous in nature as per the XRD results. The catalytic activity of the nZVI was employed for the catalytic reduction of 4-nitrophenol (4-NP) and decoloration of textile dyes such as methylene blue, methyl orange, and malachite green, respectively. The proposed nZVI synthesis method exhibited better catalytic performance toward reduction of 4-NP and degradation of dyes within 4 min for 0.1 mg of catalyst. Moreover, the synthesized catalyst nZVI can be recoverable and reutilized in many cycles without loss of its significant catalytic activity. The synthesized nZVI could be a promising material to treat industrial wastewater via profitable, sustainable, and ecofriendly approaches.

Standardization of herbal drugs is an essential aspect while considering the quality of the herbal drug, consistency in bioactive content and therapeutic efficacy. The roots, seeds and leaves of Abrus precatorius L. possesses a number of biological activities such as anti-bacterial, anti-cancer, anti-diabetic, anti-fertility, nephroprotective and antiseratonergic activity. The root of Abrus precatorius L. contains a special compound glycyrrhizin, which is an important bioactive compound widely used against cough in the Siddha, Unani and Ayurvedic system of medicines. In view of its medicinal importance, the present study was focused to standardize the Abrus precatorius L. root according to pharmacopoieal standard methods. Qualitative physicochemical studies and High Performance Thin Layer Chromatography (HPTLC) analysis were performed to identify and to assure the quality of the herbal drug.

A single pot synthesis of gellan gum coated silver nanoparticles using aniline as a reducing agent has been investigated in present study. The reaction was facile at 80 ºC under reflux condition and the complete reduction of silver ions was noted within 2 h. The resulting gellan gum protected silver nanoparticle was isolated and analyzed with various analytical tools. The antimicrobial activity of the prepared nanocomposite had shown an excellent activity against some selected pathogenic microorganisms.