Layer-by-layer Nanoarchitectonics: Invention, Innovation, and Evolution

TLDR

Nanoscale self‑assembly is increasingly important across chemistry, yet fully three‑dimensional nanostructures remain difficult to fabricate; instead, layer‑by‑layer (LbL) deposition provides a versatile, inexpensive, and rapid method for building controlled lamellar films that has attracted broad interest. This review focuses on nanoarchitectonics achieved through layer‑by‑layer assembly. The review traces the invention and history of LbL assembly, then discusses recent methodological innovations and application advances across physical, chemical/biochemical, and biomedical fields.

Abstract

Abstract Materials fabrication with nanoscale structural precision based on bottom-up-type self-assembly has become more important in various current disciplines in chemistry including materials chemistry, organic chemistry, physical chemistry, analytical chemistry, biochemistry, colloid and surface chemistry, and supramolecular chemistry. Although the design of new materials based on nanoscale self-assembly is anticipated as a key concept, preparing complete three-dimensional structures at nanoscale precision remains a difficult target using current technologies. Rather, dimension-reduced approaches such as layering of two-dimensional nanostructures into precisely controlled lamellar nanomaterials are currently achievable. In particular, layer-by-layer (LbL) assembly is known as a highly versatile method for fabrication of controlled layered structures from various kinds of component materials using very simple, inexpensive, and rapid procedures. Therefore, fabrication of multilayer films through the LbL deposition process has attracted growing interest from various research communities. The high versatility and flexibility of LbL assembly is continuously creating new concepts, new materials, new procedures, and new applications. In this highlight review, we focus on nanoarchitectonics by LbL assembly. After an initial introduction on the invention and a brief history of the LbL assembly technique, innovations and the evolution of the technique are described based mainly on recent examples, which are categorized into two sections: (i) developments in methodology (technical, material, and phenomenological aspects with expansion of concept) and (ii) progress in applications (physical, chemical/biochemical, and biomedical applications).