Layer‐by‐Layer Assembly: Recent Progress from Layered Assemblies to Layered Nanoarchitectonics

Abstract

As an emerging concept for the development of new materials with nanoscale features, nanoarchitectonics has received significant recent attention.A mongt he various approaches that have been developed in this area, the fixeddirection construction of functional materials, such as layered fabrication, offers ah elpful starting point to demonstrate the huge potentialo fn anoarchitectonics. In particular, the combination of nanoarchitectonics with layer-by-layer (LbL) assembly and al arge degree of freedomi nc omponent availability and technical applicability would offer significant benefits to the fabrication of functional materials. In this Minireview,r ecent progress in LbL assembly is briefly summarized. After introducing the basicso fL bL assembly,r ecent advances in LbL research are discussed, categorized according to physical, chemical, and biological innovations, along with the fabrication of hierarchical structures.E xamples of LbL assemblies with graphene oxide are also described to demonstrate the broad applicability of LbL assembly,e ven with afixed material.Scheme1.Outline of the nanoarchitectonics concept:afusion of nanotechnology and the other research fields, the harmonization of various actions, and the conversion of simple self-assemblyinto hierarchical structures.

Current Advances of Hollow Capsules as Controlled Drug Delivery Systems

“…LbL technique relies on sequential deposition of multiple layers of polymers onto a colloid template and subsequent dissolution of the colloidal core. It renders the ability to precisely control the thickness and composition of the capsule wall during its step‐wise polymer adsorption; moreover, multiple functional groups can be introduced during the synthesis, offering opportunities to acquire ideal materials with desired functionalities . Despite the benefits of LbL technique, it still has some drawbacks.…”

Magnetically responsive layer-by-layer microcapsules can be retained in cells and under flow conditions to promote local drug release without triggering ROS production

“…One nanoengineering approach, layer-by-layer (LbL) assembly first described by Decher et al (1992) 16 is a simple but flexible method to engineer nanoscale layers incorporating responsive particles and biological molecules into complex arrangements with functions ranging from sensors to drug delivery. [17][18][19] LbL assembly applied to microparticles was first reported by 20 by the sequential addition of layers of alternatively charged polymers of approximately 2-3 nm in thickness 21 on a template core. These microcapsules are ideally suited to the delivery of macromolecules that can be trapped within the structure of the capsule whereas small molecule drugs readily diffuse out unless they have affinity for a capsule component, 22 layers are crosslinked to improve retention 23 or high drug loading is achieved by use of crystalline drug as the capsule core.…”

The Role Played by Graphene Oxide in the Photodeposition and Surface‐Enhanced Raman Scattering Activity of Plasmonic Ag Nanoparticle Substrates

“…[10] Among the different bottom-up methodologies currently available, the layer-by-layer (LbL) technique offers several advantages for the fabrication of SERS active substrates, such as low cost, easy execution, and compatibility with different types of materials and substrate shapes. [11] The LbL technique relies on the alternate adsorption onto solid surfaces of different materials displaying complementary functionalities, which leads to the stepwise growth of film thickness with nanometer precision. In this way, the LbL film assembly is per excellence a powerful method for the construction of layered functional systems with controlled nanoarchitectonics.…”

“…In this way, the LbL film assembly is per excellence a powerful method for the construction of layered functional systems with controlled nanoarchitectonics. [11] These attractive features have been explored in the development of SERS active substrates capable of, for instance, probing the molecular arrangement of drugs within biomimetic systems, [12] simultaneous detection of tryptophan, phenylalanine, urea, and melamine, [13] detection of methenamine in foodstuffs, [14] 4-mercapto-pyridine, [15] benzenethiol, [16] and graphene oxide (GO). [17] Herein, we propose a simple yet very effective photocatalytic method that uses an LbL assembled film of TiO 2 nanoparticles (TiO 2 NP) to simultaneously act as a photocatalyst and immobilization platform for Ag nanoparticles (AgNPs) aiming at SERS applications.…”