Amino Acids and Peptides in Colloidal Nanoparticle Synthesis

Abstract

The synthesis of colloidal nanoparticles, having well-ordered structures in high yield, environmentally friendly methods and low cost, has drawn significant attention because of their diverse applications in material sciences, chemistry, biology and medicine. Generally, two distinct schools of thought, the “top-down” approach and the “bottom-up” method, have been used for the synthesis of colloidal nanoparticles. Chemical reduction is most frequently used for the synthesis of nanoparticles as stable, colloidal dispersions in solution. Among all reducing agents, amino acids, peptides and peptide mimetics are highly promising, owing to their structural diversity, self-assembly propensities, biocompatibility and biodegradability. The non-covalent interactions such as hydrogen bonding, hydrophobic, π-stacking and van der Waals interactions play a very important role in achieving the production of thermodynamically stable colloidal nanoparticles. Moreover, the balance between these non-covalent interactions can tune the shape, size and morphology of the colloidal nanoparticles. This chapter mainly focuses on the role of amino acids or small peptides as reducing agents or as a matrix to stabilize colloidal nanoparticles. Emphasis will be given on both advantages and limitations. Moreover, the chapter will compare amino acids with other reducing agents for the synthesis of colloidal nanoparticles. The recent advances and future scope in this area will be discussed briefly.