Four-Level Structural Hierarchy: Microfluidically Supported Synthesis of Polymer Particle Architectures Incorporating Fluorescence-Labeled Components and Metal Nanoparticles

Abstract

Hierarchical assemblies of functional polymer particles are promising due to their surface as well as physicochemical properties. However, hierarchical composites are complex and challenging to form due to the many steps necessary for integrating different components into one system. Highly structured four-level composite particles were formed in a four-step process. First of all, gold (Au) nanoparticles, poly­(methyl methacrylate) (PMMA) nanoparticles, and poly­(tripropylene glycol diacrylate) (poly-TPGDA) microparticles were individually synthesized. By applying microfluidic techniques, polymer nano- and microparticles were formed with tunable size and surface properties. Afterwards, the negatively charged gold nanoparticles and PMMA particles functionalized with a positively charged surface were mixed to form Au/PMMA assemblies. The Au/PMMA composites were mixed and incubated with poly-TPGDA microparticles to form ternary Au/PMMA/poly-TPGDA assemblies. For the formation of composite-containing microparticles, Au/PMMA/poly-TPGDA composites were dispersed in an aqueous acrylamide–methylenebisacrylamide solution. Monomer droplets were formed in a co-flow microfluidic device and photopolymerized by UV light. In this way, hierarchically structured four-level composites consisting of four different size ranges0.025/0.8/30/1000 μmwere obtained. By functionalizing polymer nano- and microparticles with different fluorescent dyes, it was possible to visualize the same composite particle under two different excitation modes (λex = 395–440 and λex = 510–560 nm). The Au/PMMA/poly-TPGDA composite-embedded polyacrylamide microparticles can be potentially used as a model for the creation of composite particles for sensing, catalysis, multilabeling, and biomedical applications.

Five‐Level Structural Hierarchy: Microfluidically Supported Synthesis of Core–Shell Microparticles Containing Nested Set of Dispersed Metal and Polymer Micro and Nanoparticles

“…Hierarchically constructed multi-level systems are characterized by a DOI: 10.1002/ppsc.202300030 multi-scale organization which can be achieved by assembling nano-, and microparticles together in a well-defined manner. The construction of hierarchical composites can be achieved by several methods, such as heteroaggregation, [1] electrostatic coupling, [2,3] combination of different coating techniques, [4] droplet-based microfluidic platform, [5] covalent coupling, [6] encapsulation, [7,8] Many factors can influence the formation of composite particles, such chemical composition, particle size, particle concentration, ionic strength, surface charge and the presence of surfaceactive compounds. In case of heteroaggregation, the particle assembling process is driven by the existent attractive forces as well as the tendency of particles to minimize their surface energy.…”

Uniform and Fluorescent Poly(urea-siloxane) Microspheres: Preparation and Recyclable Use as Sensors for Cr6+ and Fe3+ Detection

“…Fluorescent polymer microspheres have been gaining increased attention thanks to their potential and often unique applications in biolabeling, bioimaging, drug targeting, bioseparation, and sensing. − Fluorescent microspheres are usually synthesized by a combination of polymer particles with metal nanoparticles, quantum dots, or with organic dye compounds through physical or chemical interactions. They display usually high quantum yield and narrow emission.…”

Magnetic‐optical dual functional Janus particles for the detection of metal ions assisted by machine learning

“…Compartment‐structured microspheres can serve as microreactors [10–12] . These multicompartmental microspheres can also achieve composite functions by adding different functional components to the compartments, such as magnetic particles and luminescent molecules [13,14] …”

“…[10][11][12] These multicompartmental microspheres can also achieve composite functions by adding different functional components to the compartments, such as magnetic particles and luminescent molecules. [13,14] This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.…”