J. Santhanalakshmi

Bio: J. Santhanalakshmi is an academic researcher from University of Madras. The author has contributed to research in topics: Silver nanoparticle & Colloidal gold. The author has an hindex of 3, co-authored 3 publications receiving 731 citations.

Green Synthesis of Silver Nanoparticles Using Polyalthia longifolia Leaf Extract along with D-Sorbitol: Study of Antibacterial Activity

Abstract: Synthesis of silver nanoparticles (AgNPs) using Polyalthia longifolia leaf extract as reducing and capping agent along with D-sorbitol used to increase the stability of the nanoparticles has been reported. The reaction is carried out at two different concentrations (10−3 M and 10−4 M) of silver nitrate, and the effect of temperature on the synthesis of AgNPs is investigated by stirring at room temperature (25°C) and at 60°C. The UV-visible spectra of NPs showed a blue shift with increasing temperature at both concentrations. FT-IR analysis shows that the biomoites played an important role in the reduction of Ag

Aloe leaf extract and microwave assisted green synthesis of gold nanoparticles and its catalytic activity on reductive degradation of methyl red

Abstract: Gold nanoparticles were synthesized by adapting an ecofriendly green method using aloe leaf extract. Aloe leaf extract acts both as stabilizing as well as reducing agent. The microwave method was adopted to prepare gold nanoparticles (GNPs). The formation of GNPs was observed using Ultraviolet surface plasmon resonance (UV-SPR) analysis. Morphology and characterization of GNPs were done by using Field emission scanning electron microscopy (FESEM), High resolution transmission electron microscopy (HRTEM), Fourier transforms infrared spectroscopy (FT-IR), and Energy dispersive x-ray analysis (EDAX) techniques. FESEM and HRTEM analysis showed that the morphology of the obtained GNPs was polygon-shaped. Crystalline nature was studied using X-ray diffraction (XRD) analysis. By applying the Scherrer formula, the average size of the GNPS was estimated to be 6±1nm. The catalytic activity of the prepared nanoparticles was studied by taking methyl red reduction as a model reaction. UV-VIS spectroscopy was used to follow the reaction by observing a change in absorbance with respect to time. The reaction is monitored under pseudo first order kinetics.

Green Synthesis of Metallic Nanoparticles via Biological Entities

Abstract: Nanotechnology is the creation, manipulation and use of materials at the nanometre size scale (1 to 100 nm). At this size scale there are significant differences in many material properties that are normally not seen in the same materials at larger scales. Although nanoscale materials can be produced using a variety of traditional physical and chemical processes, it is now possible to biologically synthesize materials via environment-friendly green chemistry based techniques. In recent years, the convergence between nanotechnology and biology has created the new field of nanobiotechnology that incorporates the use of biological entities such as actinomycetes algae, bacteria, fungi, viruses, yeasts, and plants in a number of biochemical and biophysical processes. The biological synthesis via nanobiotechnology processes have a significant potential to boost nanoparticles production without the use of harsh, toxic, and expensive chemicals commonly used in conventional physical and chemical processes. The aim of this review is to provide an overview of recent trends in synthesizing nanoparticles via biological entities and their potential applications.

Biosynthesis of metallic nanoparticles using plant derivatives and their new avenues in pharmacological applications – An updated report

Abstract: The field of nanotechnology mainly encompasses with biology, physics, chemistry and material sciences and it develops novel therapeutic nanosized materials for biomedical and pharmaceutical applications. The biological syntheses of nanoparticles are being carried out by different macro-microscopic organisms such as plant, bacteria, fungi, seaweeds and microalgae. The biosynthesized nanomaterials have been effectively controlling the various endemic diseases with less adverse effect. Plant contains abundant natural compounds such as alkaloids, flavonoids, saponins, steroids, tannins and other nutritional compounds. These natural products are derived from various parts of plant such as leaves, stems, roots shoots, flowers, barks, and seeds. Recently, many studies have proved that the plant extracts act as a potential precursor for the synthesis of nanomaterial in non-hazardous ways. Since the plant extract contains various secondary metabolites, it acts as reducing and stabilizing agents for the bioreduction reaction to synthesized novel metallic nanoparticles. The non-biological methods (chemical and physical) are used in the synthesis of nanoparticles, which has a serious hazardous and high toxicity for living organisms. In addition, the biological synthesis of metallic nanoparticles is inexpensive, single step and eco-friendly methods. The plants are used successfully in the synthesis of various greener nanoparticles such as cobalt, copper, silver, gold, palladium, platinum, zinc oxide and magnetite. Also, the plant mediated nanoparticles are potential remedy for various diseases such as malaria, cancer, HIV, hepatitis and other acute diseases.