Interfacial nanoarchitectonics with porphyrins and related molecules: Langmuir-Blodgett method and layer-by-layer assembly

Nanoarchitectonics is the methodology for the architecture of nano-units of atoms, molecules, and nanomaterials to create functional material systems. This will integrate nanotechnology with other fields such as organic chemistry, supramolecular chemistry, material science, microfabrication technology, and bio-related sciences. Through this review, it is shown that nanoarchitectonics is important for the development of various functional materials. Porphyrins and their analogues are exemplified as important players in nanoarchitectonics strategies. The contents of this review can be briefly summarized as follows. First, recent examples of studies on porphyrins and their analogues, ranging from organic synthesis as basic research to biomedical applications as advanced usages, are presented. This demonstrates the broad utility of porphyrins as functional nano-units, from molecular nanoarchitectonics to material nanoarchitectonics. In subsequent sections, the organization and function of porphyrin assemblies by the Langmuir-Blodgett (LB) method and layer-by-layer (LbL) assembly are described as examples of nanoarchitectonics at interfaces. The creation of functional materials through nanoarchitectonics is rich in possibilities. Conversely, the wide range of possibilities may make it difficult to easily design and control. Confine the system from free three-dimensional space to a two-dimensional field such as an interface, and design, creation, and evaluation may become easier. The nanoarchitectonics of functional structures in a two-dimensional plane are also advantageous in terms of functional expression. The use of interfacial environments is an extremely powerful tool for creating functional systems through nanoarchitectonics.