Contents


Preface

It gives us immense pleasure to introduce this book called *Gold Nanoparticles— Reaching New Heights*, based on the state of the art of gold nanoparticles (AuNPs) with their outstanding and potential applications. The book deals with the

the nano level.

field.

advanced nanotechnological aspects of synthesis, characterization, development, and potential optical and biological applications of AuNP materials. Discussion of these aspects develops through the fundamental and applied experimental routes using conventional methods via the interaction of AuNPs and finally brings together both scientific and technological worlds. Basically, AuNPs have undoubtedly achieved many accomplishments in a conventional sense and have taken new directions from preparation to practical applications in research and development in different areas of science and technology. New paths and emerging frontiers branch out from time to time from this advanced nanotechnology stage of low nanodimensional AuNPs. Advances in AuNPs with instrumentation for evaluating the structural model in aqueous or non-aqueous phases now enable us to understand quite broadly almost all the events that take place with gold AuNPs at least at

In this book, authors Gavino et al. focus on the design of colorimetric sensors and probes due to their interesting photophysical properties. In this approach, the surface plasmon resonance (SPR) band is sensitive to the proximity of other nanoparticles and thus analyte-triggered aggregation of AuNPs results in an important bathochromic shift of the SPR band and a change in the color of the solution from red to blue due to interparticle surface plasmon coupling. The selectivity of AuNPbased sensors towards different analytes depends on the recognition properties of the molecules attached to the surface of the nanoparticles. Finally, a selection of biologically active molecules is considered as analytes: neurotransmitters, nerve agents, pesticides, and carboxylates of biological interest. Taking into account the interesting photophysical properties of AuNPs, their easy functionalization, the use of aqueous solutions, and detection using the naked eye, they conclude that the red or blue question will continue to be ever present in the molecular sensing

Qureshi et al. also approach the higher catalytic activity being observed for AuNPs supported on reducible metal oxides such as TiO2, CO3O4, CeO2, and Fe2O3. Here, they study in detail CO oxidation catalyzed by mono- and bimetallic AuNPs over various silica supports. Finally, it is true to say that silica-supported gold nanocatalysts are becoming a hot topic of research for CO oxidation; conversely, there are still many challenges ahead for the improvement of silica-supported gold nanocatalysts to fulfill the main necessities of any catalyst such as an easy and low-cost synthesis method, high activity, selectivity, and greater stability at lower temperatures. Furthermore, they conclud that the proof of identity for active gold species is

Briggs et al. approach nanoparticle interactions with energetic neutrons, photons, and charged particles that can cause structural damage ranging from single atom displacement events to bulk morphological changes. Due to the diminutive length

still a challenging task for CO oxidation reactions catalyzed by gold.
