The Many Ways to Assemble Nanoparticles Using Light

Abstract

The ability to reversibly assemble nanoparticles using light is both fundamentally interesting and important for applications ranging from reversible data storage to controlled drug delivery. Here, the diverse approaches that have so far been developed to control the self-assembly of nanoparticles using light are reviewed and compared. These approaches include functionalizing nanoparticles with monolayers of photoresponsive molecules, placing them in photoresponsive media capable of reversibly protonating the particles under light, and decorating plasmonic nanoparticles with thermoresponsive polymers, to name just a few. The applicability of these methods to larger, micrometer-sized particles is also discussed. Finally, several perspectives on further developments in the field are offered.

Light‐Driven Proton Transfer for Cyclic and Temporal Switching of Enzymatic Nanoreactors

“…Over the last two decades, a plethora of light‐responsive materials for different applications have been developed. [ 1–24 ] Light is a highly attractive stimulus due to its high spatial and temporal resolution, controllability, and non‐invasiveness. Owing to these characteristics, light can precisely orchestrate the isomerization, mobility, and degradation of chromophores for various processes, such as reversible operation of molecular machines, [ 25–28 ] switching of vesicles and nanocapsules, [ 14,29–33 ] bioimaging of molecules and compartments, [ 16,18,21,23,24,34 ] and dynamic self‐assembly of nanoparticles and vesicles.…”

“…Moreover, previous efforts have paved the way to create self‐adaptive [ 41 ] and light‐responsive, wavelength‐selective [ 31,32 ] polymersomes with switchable membrane permeability for the release of cargo and control of enzymatic reactions “on demand”. This stimulated us to search for a further simplification of self‐adaptive, pH‐responsive polymersomes [ 41 ] as organelle mimics with desired out‐of‐equilibrium properties, leading to the concept of light‐driven proton‐transfer [ 11,12,20,22,27 ] through the reversible transformation of protonated‐merocyanine/spiropyran (MEH/SP) pair ( Scheme ).…”

Time-encoded bio-fluorochromic supramolecular co-assembly for rewritable security printing

“…[20][21][22][23] In this respect, uorochromic supramolecular assemblies triggered by heat, light, solvent, vapor and force have drawn great enthusiasm. [24][25][26][27][28] Among them, bio-uorochromic assembly is of particular interest, because of its possible transient characteristics in response to biological sources, which can be regarded as a superior candidate for smart uorescent materials. Nevertheless, reports highlighting bio-uorochromic assembly and biofueled transient assembly [29][30][31][32][33][34] in one system have been rarely exploited so far, but need to be addressed because they are closer to the naturally occurring system and more efficient in some specic scenarios.…”

Driving Smart Molecular Systems by Artificial Molecular Machines

“…In response to irradiation, the azo group (NN) of azobenzene undergoes photoisomerization, inducing a transition from thermally stable trans ‐isomer to the photostable cis ‐isomer, with the reverse process observed upon exposure of the latter isomer to long wavelength or heating. This reversibility, along with the relative ease of chemical modification, makes azobenzene and its derivatives popular components of stimuli‐responsive systems . 3) Molecular motors, representing the third type of molecular machines, undergo unidirectional motion under external energy input and are fundamentally different from molecular switches; i.e., the former can progressively drive systems away from equilibrium and continuously perform work in nonequilibrium environments for a full cycle, whereas the latter cannot.…”