COORDINATIVE STUDY OF ORGANIC MATERIAL CAPPING ON GOLD AND SILVER NANOPARTICLE FOR APPLICATION IN COLORIMETRIC SENSOR

• Main Author: Abrori Syakuro, Qoid
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/80826
• Institution: Institut Teknologi Bandung

Gold and silver nanoparticle (AuNP and AgNP) have been applied in various field in nanotechnology because of its unique optical properties such as localized surface plasmon resonance (LSPR). LSPR is phenomenon that appears from interaction between photon and metallic nanoparticle that give nanoparticle different properties from their bulk form. Metallic nanoparticle usually consists of two part which are the metallic core and capping molecule that act as stabilizer and the protector of metallic nanoparticle core. The surface of nanoparticle can be functionalized with molecule likes citrate or 3-mercaptopropionic acid (3-MPA) so it has potential application as the probe of biosensor device. The physical and chemical properties of metallic nanoparticle ar`e not only determined by its ion and building component but also influenced by interaction between capping molecule and metallic core. There have been a lot of research about the coordination between organic molecule with metallic core, but the study about the coordination of metallic nanoparticle still haven’t reach the final conclusion. For this reason, study of synthesis of AuNP and AgNP by use of modified reduction method was carried out to optimize the synthesis of gold and silver nanoparticle capped by citrate or 3-MPA can be stable enough. Moreover, study of interaction between capping molecule (citrate and 3-MPA) with gold and silver as well as colorimetric testing with Biocytin and Avidin was also done. Optical and chemical characterization of AuNP and AgNP was carried out by ultraviolet-visible (UV-Vis), fourier transform infrared (FTIR), and Raman spectroscopy. Meanwhile, the morphology and size of nanoparticle was done with transmission electron microscopy. The characterization result shows that Au-citrate and Au-MPA has a sharp absorption peak respectively at wavelength 524 nm and 526 nm while Ag-citrate and Ag-MPA has absorption peak at approximately 420 to 456 nm. FTIR and Raman characterization result show the difference in frequencies of vibration for some coordination between AuNP, AgNP and the free capping molecule which are caused different chemical interaction and effect of the LSPR. Colorimetric tests have not yet shown any observable color changes but have shown signs of aggregation.