Investigation of properties of agarose gel embedded with gold nanoparticles

The main objective of this thesis is to incorporate gold nanoparticles into agarose and measure the properties. Not much work is done in this field to incorporate nanoparticles into polymers for studying the optical and dielectric properties. The incorporation of gold nanoparticles is done using three methods. The first method includes the reduction of tetrachloroaurate trihydrate using agarose. The second method involves the addition of agarose to tetrachloroaurate trihydrate and reduces the composite with trisodium citrate. The third method involves the preparation of gold nanoparticles by citrate reduction method and then addition of agarose powder to make the colloidal gold solution to become gel. Nine samples were prepared using three methods with different concentrations of tetrachloroaurate trihydrate, trisodium citrate and agarose. The Transmission Electron Microscopy images revealed that gold nanoparticles agglomerate and form clusters in the gel due to the presence of two reducing agents and high pH citrate. Through aging analysis, the optical properties showed the shift in peaks and the formation of secondary peaks due to clusters in some samples. The electrical properties showed that the impedance decreases with time and capacitive reactance is indirectly proportional to frequency.