Ligand protected noble metal nanoparticles are excellent building blocks for colloidal self‐assembly. Metal nanoparticle self‐assembly offers routes for a wide range of multifunctional nanomaterials with enhanced optoelectronic properties. The emergence of atomically precise monolayer thiol‐protected noble metal nanoclusters has overcome numerous challenges such as uncontrolled aggregation, polydispersity, and directionalities faced in plasmonic nanoparticle self‐assemblies. Because of their well‐defined molecular compositions, enhanced stability, and diverse surface functionalities, nanoclusters offer an excellent platform for developing colloidal superstructures via the self‐assembly driven by surface ligands and metal cores. More importantly, recent reports have also revealed the hierarchical structural complexity of several nanoclusters. In this review, the formulation and periodic self‐assembly of different noble metal nanoclusters are focused upon. Further, self‐assembly induced amplification of physicochemical properties, and their potential applications in molecular recognition, sensing, gas storage, device fabrication, bioimaging, therapeutics, and catalysis are discussed. The topics covered in this review are extensively associated with state‐of‐the‐art achievements in the field of precision noble metal nanoclusters.

Despite tremendous progress in the field of fluorescence-based anticounterfeiting, the advanced anticounterfeiting techniques are still posing challenges all over the world due to their cost and reliability. Recently, light-emitting atomically precise nanoclusters have emerged as attractive building blocks because of their well-defined structure, function, and stable photoluminescence. Herein, we report the room temperature fabrication of a stable, flexible, nontoxic, and low-cost precision nanocluster-based luminescent ink for the stencil printing of an optically unclonable security label. Nanocluster-based printing ink shows brilliant photoluminescence owing to its extended C− H•••π/π•••π interactions. Spectroscopic and microscopic investigations show that intercalated nanoclusters in the printed security labels are highly stable as their optical features and molecular compositions are unaffected. The exceptional mechanical, thermal, photo, and aqueous stabilities of the printed security labels endorse to demonstrate the printing and smartphone-based electronic reading of the quick response code on a currency. Finally, confidential information protection and decryption under a precise window of light have been achieved by adopting the optical contrast illusion. The overall cost of the security label is found to be approximately 0.013 USD per stamp.