Towards understanding the influence of physio-chemical environment on biological synthesis of inorganic materials

Mother Nature is replete with mechanisms that enable self-assembly at the nanoscale to produce a myriad of inorganic materials with precise dimensions, controlled morphology and high complexity from the assemblage of many smaller and simpler components. This has triggered multidisciplinary research at the threshold where biology meets chemistry and physics. The formulation of these nanostructures appears simple, yet is achieved using complex biochemical pathways. Elucidating the complexity of Nature’s artwork has long been a source of inspiration for materials scientists. The attempt at designing strategies to create inorganic nanomaterials has led to the development of biological ‘Green’ synthesis routes over the past decade or so. This approach typically encompasses biosynthesis (use of live organisms) and biomimetic (use of biomacromolecules) routes and has revolutionised the aspect of nanoparticle synthesis. The challenge now lies in understanding the underlying principles/mechanisms employed by nature towards the synthesis and assembly of these technologically important nanomaterials into complex 3D morphologies.

Although biological routes have been well-studied, the role of physico-chemical environment during the synthesis of nanomaterials is still a relatively unexplored niche wherein there is limited or no information. The main objective of this research is to understand the critical role of physico-chemical environment during biological synthesis of materials that would help elucidate the complex supramolecular chemistry involved in the formation of the intricate and ornate morphologies. This research would, in a nutshell, provide information on some of the underlying fundamental principles employed by Nature during the synthesis and assembly of bioinorganic nanomaterials.

The research work outlined herein is split into two distinct aspects that typically involve biosynthesis (metallic silver and copper nanoparticles) and biomimetic synthesis (silica particles). Although the two aspects concentrate on different systems, essentially the common theme of the important role of physico-chemical environments in controlling biomineral morphologies links the different chapters of this thesis.