Surface ligand-directed aggregation: Controlling the thermodynamics and products of self-assembly 

Most of the captivating functions surrounding us occur through the complex network of interacting particles. As a result, there is a great interest in arranging individual materials into the complex matter, with the aim of achieving functions similar to those observed in nature. In this context, the process of self-assembly is arguably the most efficient way to organize particles into well-ordered structures. Our group is interested in the ‘interplay of forces’ to control the thermodynamics (equilibrium and non-equilibrium) and products of nanoparticle self-assembly. Here again, the ‘ligand of choice’ approach can be an attractive strategy to dictate the pathway, final state, and property of nanoparticle self-assembly. In one of the first reports, our group revealed the formation of ‘controlled aggregates’ in nanoparticle systems by regulating the strengths of different interparticle forces. In a similar way, the property of selectivity was introduced in inherently nonselective gold nanoparticles toward toxic metal ions: “seeing” with “blind” nanoparticles. In the area of dynamic self-assembly, a transient switching between completely precipitated and redispersed stages of nanoparticles was demonstrated by establishing temporal changes in the interparticle interactions: “transiently stable nanoparticle precipitates”. In the area of nano-bio self-assembly, the power of precise control over interparticle interactions helped in retaining the inherent properties of the biomolecules as well as the nanoparticles in the self-assembled structures, which indeed is not a trivial task. We termed these long-ranged bio-nano assemblies as “bioplasmonic network”.

Representative Publications: Angew. Chem. Int. Ed. 2022Chem. Mater. 2022 .


Students in-charge: Sumit Roy