Background : Nature offers an extraordinary molecular toolbox for organizing matter with remarkable precision. Inspired by this capability, biohybrid materials combine the structural complexity and chemical versatility of biological macromolecules with the unique electronic, optical, and catalytic properties of inorganic nanomaterials. Among these systems, protein- and DNA-templated metal nanoclusters represent an exciting class of materials in which biological scaffolds provide confined molecular environments for controlling metal nucleation, cluster growth, and stabilization.

Unlike conventional metal nanoparticles, ultrasmall metal nanoclusters contain a limited number of metal atoms and often exhibit discrete electronic states, size-dependent photoluminescence, and distinctive redox properties. Proteins offer diverse amino acid coordination sites and three-dimensional architectures, while DNA provides sequence-dependent metal-binding environments and programmable molecular organization. Together, these biological templates offer opportunities to tune nanocluster composition, nuclearity, stability, and electronic structure through molecular-level interactions.