Lateral nanoarchitectonics from nano to life: ongoing challenges in interfacial chemical science

Lateral nanoarchitectonics is a method of precisely designing functional materials from atoms, molecules, and nanomaterials (so-called nanounits) in two-dimensional (2D) space using knowledge of nanotechnology. Similar strategies can be seen in biological systems; in particular, biological membranes ingeniously arrange and organise functional units within a single layer of units to create powerful systems for photosynthesis or signal transduction and others. When our major lateral nanoarchitectural approaches such as layer-by-layer (LbL) assembly and Langmuir-Blodgett (LB) films are compared with biological membranes, one finds that lateral nanoarchitectonics has potential to become a powerful tool for designing advanced functional nanoscale systems; however, it is still rather not well-developed with a great deal of unexplored possibilities. Based on such a discussion, this review article examines the current status of lateral nanoarchitectonics from the perspective of in-plane functional structure organisation at different scales. These include the extension of functions at the molecular level by on-surface synthesis, monolayers at the air-water interface, 2D molecular patterning, supramolecular polymers, macroscopic manipulation and functionality of molecular machines, among others. In many systems, we have found that while the targets are very attractive, the research is still in its infancy, and many challenges remain. Therefore, it is important to look at the big picture from different perspectives in such a comprehensive review. This review article will provide such an opportunity and help us set a direction for lateral nanotechnology toward more advanced functional organization.