The unique property of the silver nanoparticles having the antimicrobial activity drags the major attention towards the present nanotechnology. The environmentally nontoxic, ecofriendly, and cost-effective method that has been developed for the synthesis of silver nanoparticles using plant extracts creates the major research interest in the field of nanobiotechnology. The synthesized silver nanoparticles have been characterized by the UV-visible spectroscopy, atomic force microscopy (AFM), and scanning electron microscopy (SEM). Further, the antibacterial activity of silver nanoparticles was evaluated by well diffusion method, and it was found that the biogenic silver nanoparticles have antibacterial activity against
The broad spectrum of nanotechnology is important in the major fields of biology, chemistry, physics, and material sciences. Nanotechnology deals with the study of materials at the nanometers [
Plant extracts include bark, root, leaves, fruit, flowers, rhizoids, and latex and are used to synthesize the nanoparticles. These nanoparticles show different dimensions including the size, shape, and dispersion which have more efficacy than those synthesized from the chemical and physical procedures. Therefore, the use of green plants for similar nanoparticle biosynthesis methodologies is an exciting possibility which has compatibility for pharmaceutical and other biomedical applications, as they do not use toxic chemicals for the synthesis of nanoparticles [
Nanoparticles had a wide variety of application in the major fields of medicine, electronics, therapeutics, and diagnostic agents. Silver nanoparticles have wide application in biomedical science like treatment of burned patients, antimicrobial activity and used the targeted drug delivery, and so forth [
All analytical reagents and media components were purchased from HiMedia (Mumbai, India) and Sigma Chemicals (St. Louis, MO, USA).
The fresh bark of
Silver nanoparticles (AgNO3) were synthesized by reducing the freshly prepared 1 mM silver nitrate and stored under dark conditions with the bark extract. The reaction mixture was prepared in ratio of 9 : 1 (V/V) of freshly prepared silver nitrate solution and bark extract, respectively. The initial color of the solution was observed.
The silver nanoparticles show the plasmon resonance at 400 to 450 nm in the UV-Visible spectrum. The UV-Visible spectrum of synthesized silver nanoparticles was analysed by spectrophotometer (LAB INDIA UV 300+).
Atomic force microscopy is an advanced characterization technique to identify the size, shape, and dispersion of the silver nanoparticles. In order to characterize the silver nanoparticles, the sample was prepared by sonication at room temperature for about 15 minutes in the ultrasonicator. Then the sample solution was dried as a thin layer on mica-based glass slide which was used to view under the AFM Model NT-MDA Solver.
SEM analysis of the silver nanoparticles provides the information regarding the dimensions including the surface, shape, and size. The sample was prepared by sonicating the sample solution for 15 minutes at room temperature. A small drop of sonicated sample was dried on a glass slide, and it was coated by gold and observed under ZEISS EVO HD SEM.
The antibacterial property of the silver nanoparticles was determined by using the bacterial species including the pathogenic bacteria such as
The green synthesis of silver nanoparticles using
The formation of silver nanoparticles was confirmed through measurement of UV-Visible spectrum of the reaction mixture. The UV-Visible spectrophotometric analysis of colloidal reaction mixture of silver nanoparticles synthesized using
UV-visible spectrum of silver nanoparticles.
The atomic force microscopy (AFM) results display the surface morphology of the monodispersed silver nanoparticles using
Atomic force microscopy. (a) Image of synthesized silver nanoparticles and (b) its histogram.
The biosynthesized silver nanoparticles were characterized by scanning electron microscopy for their morphology and size. The SEM micrograph reveals that the synthesized silver nanoparticles have spherical morphology with size range from 20 to 60 nm and also indicated that the particles are well separated showing no agglomeration (Figure
SEM images of silver nanoparticles synthesized by
The different species of bacteria show zone of inhibition in the well diffusion method of antimicrobial activity. The different patterns of the zone of inhibitions are observed in Figure
Antibacterial effects varying the concentrations of silver nanoparticles samples, (a) lower concentrations (2, 5, 10, and 15
Antibacterial activity of
The biological synthesis of the silver nanoparticles is rapid, ecofriendly, cost-effective, and simple method of synthesis. In the present study-silver nanoparticles are synthesized at room temperature within a less span of time. The synthesized silver nanoparticles were characterized by UV-visible spectrometer, AFM, and SEM analysis. The size of the nanoparticles ranges from 20 to 60 nm with spherical shape. AFM and SEM reveal that the synthesized silver nanoparticles are well dispersed showing no agglomeration. These nanoparticles showed a broad spectrum antimicrobial activity against both Gram positive and Gram negative bacteria. Investigation on the antibacterial activity of synthesized silver nanoparticles using
The authors declare that they have no conflict of interests.
The authors are thankful to Drs. Gaurav Raikhy and Ravi Mani Tripathi, Amity University, India, for critically reading the paper and analyzing the data.