Gold nanoparticles in organic systems: Applications in catalysis, sensors and electronics

Nanoparticles have generated intense interest over the past decade due to their potential applications in various diverse areas of science and technology. Metallic nanoparticles exhibit unusual chemical, optical, physical and thermal properties due to the presence of a large proportion of high-energy surface atoms, and to the nanometer-scale mean free path of an electron. Scientists from the multidisciplinary areas have paid considerable attention to gold nanoparticle based research due to the metal's superior stability, unique optical property and potential applications in catalysis, biology, and electronics. Gold nanoparticles have been known to exhibit properties sensitive to their matrix and hence there has been an interest in trying to understand the nature of the species that stabilize and associate with such nanoparticles. Gold nanoparticles combined with different organic molecules as well as various polymers can form hybrid materials producing interesting physical properties. Polymer supported gold nanoparticles have been shown to yield excellent performance in biological sensor systems. More recently, non-volatile memory devices have been fabricated using gold nanoparticle-polymer based composites. Many possible applications employing gold-organic systems have been explored; many devices have been studied; more potential applications are being proposed. Such composites are discussed in this review on the basis of the techniques used for their synthesis, their properties and possible applications.