Synthesis of Gold Particles and Their Use for Chemical Sensing Assignment

Synthesis of Gold Particles and Their Use for Chemical Sensing - Assignment Example e it clear that the gold was eligible since there was a continued accumulation that was evident by the change in the color of the solution from red to Purple color. It is important to test the foods sold in commercial markets. Notably, it had been discovered some sold in the commercial markets are toxic. For examples, some years ago, foods containing melamine were found in stores in China. Foods that contain melamine are toxic and are not fit for human consumption. Thus, foods that were found in stores in China were poisonous. Fortunately, a solution to this problem has been found. The use of citrate ions prevents the accumulation of layers of gold thereby hindering the formation of melamine that prevent the formation of nanoparticles on the surface of gold. This process enables shielding continued reaction of the gold layers. When such interactions occur in food gold solution that causes coloration of food is formed. The particle size having effects on gold can also be determined through photography. The size of gold particles ranges from 10 to 20 nm reflect light of different colors particularly red that turns to blue or purple if larger. The refore, the chemical test for melamine can reveal varied collect chemical properties that can help in drawing conclusions. Usually, there is a color changes from red to blue when a solutions nitrate ions and gold particles are mixed. The significance of this chemical experiment lies in this interaction Procedure. Take 0.2 mL of 100 mM gold salt stock solution and add 20 mL of distilled water to make 20 mL of 1mM gold salt solution. Then take 20 mL of the 1mM NaAuCl4 and place it into 50mL beaker. Place the beaker and its content hot plate and stirred the mixture using a magnetic stir bar. Heat the solution until it boil. When the solution begins boiling, add 2 mL of 38.8 mM solution of trisodium citrate dehydrate (Na3C6H5O7.2H2O). The gold solution forms gradually as the citrate reduces the Au ions to the neutral gold