Printing large-scale nanoparticle superlattices for multichannel detection

Challenges in the emerging applications of superlattices integrated into functional devices necessitate scalable, high-quality, and patterned architectures. These bottlenecks result from the complexity of assembly pathways and a lack of understanding of the key factors that determine the order degree. In this study, we constructed highly ordered superlattices by adding excessive nonvolatile ligands. The dynamics of the assembly process was observed in real time by in situ Raman spectroscopy, which revealed that the excess ligands reduced the diffusion velocity and extended the time for nanoparticles to self-regulate at the evaporation front. Pixelated superlattice architectures were produced on demand over large areas using inkjet printing techniques. Furthermore, a multichannel surface-enhanced Raman scattering (SERS) detection chip was developed. The SERS chip allows repeated detection of a sample and simultaneous detection of multiple analytes without interference. A new understanding of assembly behavior provides broad opportunities for the development and production of superlattice-related devices.