Layer-by-Layer Assembly of Light-Responsive Polymeric Multilayer Systems

Layer-by-Layer (LbL) assembly is a simple and highly versatile method to modify surfaces and fabricate robust and highly-ordered nanostructured coatings over almost any type of substrate. Such versatility enables the incorporation of a plethora of building blocks, including materials exhibiting switchable properties, in a single device through a multitude of complementary intermolecular interactions. Switchable materials may undergo reversible physicochemical changes in response to a variety of external triggers. Although most of the works in the literature have been focusing on stimuli-responsive materials that are sensitive to common triggers such as pH, ionic strength, or temperature, much less has been discussed on LbL systems which are sensitive to non-invasive and easily controlled light stimulus, despite its unique potential. This review provides a deep overview of the recent progresses achieved in the design and fabrication of light-responsive LbL polymeric multilayer systems, their potential future challenges and opportunities, and possible applications. Many examples are given on light-responsive polymeric multilayer assemblies built from metal nanoparticles, functional dyes, and
metal oxides. Such stimuli-responsive functional materials, and combinations among them, may lead to novel and highly promising nanostructured smart functional systems well-suited for a wide range of research fields, including biomedicine and biotechnology.