Nanomechanical Microfluidic Mixing and Rapid Labeling of Silica Nanoparticles using Allenamide-Thiol Covalent Linkage for Bioimaging

Rapid surface functionalization of nanomaterials using covalent linkage following “green chemistry” remains challenging, and the quest for developing simple protocols is persisting. We report a nanomechanical microfluidic approach for the coupling of allenamide functionalized organic derivatives on the surface of thiol-modified silica nanoparticles using allenamide-thiol chemistry. The coupling principle involves the use of a microfluidic surface acoustic wave device that generates acoustic streaming-based chaotic fluid micromixing that enables mixing of laterally flowing fluids containing active components. This approach was used to demonstrate the direct surface labeling of thiol-modified silica nanoparticles using a selected group of modified fluorescent tags containing allenamide handles and achieved a total labeling efficiency of 83–90%. This green approach enabled a highly efficient surface functionalization under aqueous conditions, with tunable control over the conjugation process via the applied ...