Investigation on curcumin mediated green solid state synthesis of conjugated silver nanoparticles and its application -

Abstract

Metallic nanoparticles have considerably advanced in the field of nanotechnology for catalytic and sensor application; especially, silver nanoparticles (Ag NPs) have attracted extensive research interest due to their potential uses in catalytic and biomedical sensor development. Although preparation of Ag NPs could be simple and straight forward, the size distribution of synthesized Ag NPs and their application can be challenging. Achieving the mono-disperse nano-size and stable Ag NP products are still challenging. Of course, one emerging field to synthesize Ag NPs has been developing green synthetic routes due to (a) their environmental friendly methods to reduce waste, and (b) minimum possible toxicity of the materials formed. Curcumin is a member of ginger family and used as a spice, a cosmetics ingredient, a food flavoring and coloring reagent. Recently it is being used as supplement by various pharmaceutical companies and this market is exponentially growing. Curcumin is non-toxic and environmental friendly. In this thesis, I synthesized curcumin conjugated Ag NPs using a solid state green approach by using curcumin and AgNO3. The synthetic condition optimized in four different temperatures 4°C, room temperature (~20 °C), 40 °C and 60 °C at ten different times, such as, 1, 2, 4, 8, 16 hours and 1, 2, 3, 5, and 7 days. This synthesis process gave us different size and shape of curcumin conjugated Ag NPs, which we investigated by various morphological and spectroscopic techniques. The growth of curcumin conjugated Ag NPs were studied in two different environments. In the first part, the growth medium was in an organic phase such as ethanol. Ag NPs obtained in this method were subsequently tested as catalysts for the reduction reaction of 4-nitrophenol to 4-aminophenol by using NaBH4 as a reducing reagent, as well as a bio-sensing agent for detecting different concentration of 6-O-palmitoyl-L-ascorbic acid. In the second part, growth medium during the solid state synthesized curcumin c