An aggregative growth process for controlling size, shape and composition of metal, alloy and core-shell...

Metal nanoparticles, especially gold and its alloy, core-shell, or nanocomposites function as theranostic probes or vehicles with amplified optical, spectroscopic, electrical and magnetic signals, or unique bio-functional, bio-compatible properties upon the desired bio-conjugation. Exploration of these functions is inherently linked to the ability to control the size, shape, composition, and surface properties, which depends to a large degree on the understanding of the controllability of these nanostructure parameters in the synthesis and processing. Aggregative growth constitutes an important pathway for the control of size, shape and composition in synthesis and processing of nanoparticles. This article highlights recent progress in the exploration of aggregative growth for the control of size, shape, and composition of metal nanoparticles. Examples such as thermally-activated aggregative growth of gold, copper, copper sulfide, alloy nanoparticles, and core-shell nanoparticles with magnetic cores and gold shells are discussed. The focus is to highlight the significance of understanding the mechanistic aspects in establishing the controllability over size, shape, and composition for further harnessing the unique nanoscale properties toward desired bioapplications.