Colloidal Plasmonic Metasurfaces for the Enhancement of Non-Linear Optical Processes and Molecular Spectroscopies

Colloidal metasurfaces are emerging as promising candidates for the development of functional chemical metamaterials, combining the undisputed control over crystallography and surface chemistry achieved by synthetic nanochemistry with the scalability and versatility of colloidal self-assembly strategies. In light of recent reports of colloidal plasmonic materials displaying high-performing optical cavities, this Minireview discusses the use of this type of metamaterials in the specific context of non-linear optical phenomena and non-linear molecular spectroscopies. Our attention is focused on the opportunities and advantages that colloidal nanoparticles and self-assembled plasmonic metasurfaces can bring to the table compared to more traditional nanofabrication strategies. Specifically, we believe that future work in this direction will express the full potential of non-linear molecular spectroscopies to explore the chemical space, with a deeper understanding of plasmon-molecule dynamics, plasmon-mediated processes, and surface-enhanced chemistry. Recent developments in colloidal-based plasmonic metasurfaces unlocked new opportunities for the application of these highly dynamic systems to non-linear optical phenomena and molecular spectroscopies. This Minireview summarizes potential advantages and current challenges of colloidal systems for the enhancement of second and third order light-matter interactions and offers a critical perspective on their potential impact on the next generation of photonics metamaterials. image