Green Synthesis of Silver Nanoparticles using Citrullus lanatus fruit rind extract.

A paper presentation at the 3rd East African Multidisciplinary Research Conference (EAMARC III) held at the United States International University- Africa, 15th -17th November, 2016.Nanotechnology is the design, characterization, production and application of materials, devices and systems by controlling the shape and size of the nanometre (10-9 m) scale Nanoparticle: (1-100nm)-the building blocks of Nanomaterials Nanoparticles have unique physical and chemical properties that are different from those of the bulk due to their large surface area to volume ratio and their smaller siz

Green Synthesis and Characterization of Silver Nanoparticles Using Citrullus lanatus Fruit Rind Extract

A Journal Article by Dr. Naumih an Associate Professor in the School of Pharmacy and Health Sciences at USIU-Africa.The wide-scale application of silver nanoparticles (AgNPs) in areas such as chemical sensing, nanomedicine, and electronics has led to their increased demand. Current methods of AgNPs synthesis involve the use of hazardous reagents and toxic solvents. There is a need for the development of new methods of synthesizing AgNPs that use environmentally safe reagents and solvents. This work reports a green method where silver nanoparticles (AgNPs) were synthesized using silver nitrate and the aqueous extract of Citrullus lanatus fruit rind as the reductant and the capping agent. The optimized conditions for the AgNPs synthesis were a temperature of 80∘ C, pH 10, 0.001 M AgNO3, 250 g/L watermelon rind extract (WMRE), and a reactant ratio of 4 : 5 (AgNO3 to WMRE). The AgNPs were characterized by Ultraviolet-Visible (UV-Vis) spectroscopy exhibiting a max at 404 nm which was consistent with the spectra of spherical AgNPs within the wavelength range of 380–450 nm, and Cyclic Voltammetry (CV) results showed a distinct oxidation peak at +291 mV while the standard reference AgNPs (20 nm diameter) oxidation peak occurred at +290 mV, and Transmission Electron Microscopy (TEM) revealed spherical shaped AgNPs. The AgNPs were found to have an average diameter of 17.96 ± 0.16 nm

Spectro-electrochemical Characterization of Anti-Schistosoma-Gold Nanoparticle Conjugate for use in Immunoassays

A Journal Article by Dr. Naumih, a Lecturer in the School of Pharmacy at USIU -AfricaGold nanoparticles(AuNPs) have been used widely in biomedical diagnostic and imaging. Their high stability, ease of characterization and ability to bind with biological molecules are among the properties that promote their diverse applications. Of interest is the application as electrochemical markers especially in immuno histochemistry, biosensors and immunoassays. In order to serve that role, an antibody needs to be attached to the surface of the nanoparticle since proteins readily bind to AuNPs. However, this immobilization process might result in nanoparticle aggregation or the loss of the bioactivity of the conjugated antibodies. We hereby report the optimization of the covalent binding of anti-schistosome antibody to AuNPs via a carbodiimide cross-linker The characterization and functionality testing of the conjugation was done using UV/Vis spectrometry and electrochemically by cyclic voltammetry(CV). The conjugate was tested with varying concentrations of Soluble Egg Antigen (SEA) as the analyte. The signal response was directly proportional to the concentration of SEA. A plot of concentration of SEA against the change in current gave a limit of detection of 3.31×10-5ng/ml based on 3 times the standard deviation of the blank. These findings demonstrated the potential for development of a point-of-care immunosensor for rapid diagnosis of Schistosomiasis