Friday, 24 January 2020

Green Synthesis of Gold Nanoparticles by Leaf Extract

Green Synthesis of Gold Nanoparticles by Leaf Extract
    Fresh leaves of Neem, Bottle Brush or F. Panda, Tetrachloroauric acid (HAuCl4·3H2O), Deionized Water, Beaker, Buret, Magnetic Stirrer with Temperature option, FIlter Paper
  2. STEP 1.
    Take fresh leaves of Neem or any other leaves you want. Wash properly and cut them into small pieces.
  3. STEP 2.
    Take Leaf pieces (25g) and mix with Deionized Water (100ml).
  4. STEP 3.
    Now boil the Leaves at around 80-90ºC for 5-10 minutes.
  5. STEP 4.
    When the water turns GREEN, filter it out and use it as reducing and capping agent for Nanoparticles synthesis.
  6. STEP 5.
    Take Tetrachloroauric acid (50mg) in deionized water (100ml); and set temperature 80ºC.
  7. STEP 6.
    Add leaf extract drop wise until the color of Tetrachloroauric acid solution turns into Red or Violet (Depends on the size of Gold Nanoparticles; further depends on the type of leave you have taken).
    The Red or Violet color indicated the formation of Gold Nanoparticles in water. UV-Vis spectroscopy absorption peak would be obtained around 530nm.
  9. Factors Affecting Synthesis
    Species of Plant/Tree: Different types of Plants/Trees are having different types of chemical composition and concentration of specific chemical in its leaves. So different species of Plants/Trees can give the different particle size, size distribution. Even morphology can also be changed by using leaf extract of different plants/trees.
    Concentration of Tetrachloroauric acid: Tetrachloroauric acid is used as the precursor in this synthesis. Higher the concentration of Tetrachloroauric acid, more the chances of agglomeration; further leads to bulky size particles.
    Concentration of Leaves in Water: Concentration of leaves in water is very important for Nanoparticles synthesis. Higher concentration of leaves in water, leads to higher concentration of reducing and capping agent in water.
    Temperature: The temperature is another important factor in the synthesis of Nanoparticles, change in temperature leads to change in the particles size; also higher temperature leads to faster chemical Kinetics.
  10. NOTE: All the experiments should be done under the guidance of lab Incharge; and proper lab safety instructions.