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

Abstract

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 field. The dye-labeled silica particles were characterized using various analytical techniques and found to be biocompatible with potential in live cell bioimaging. It is envisaged that this bioconjugation strategy will find numerous applications in the field of bioimaging and drug delivery.

Microfluidic Generation of Nanomaterials for Biomedical Applications

“…Organic, metallic and metal‐organic fluorophores can be easily doped on the surface of silica NPs, with a wide range of emission wavelengths. For example, Sreejith et al proposed a single‐phase microfluidic chip combined with acoustic streaming to produce allenamide‐thiol link on the surface of silica NPs . This microfluidic approach allowed for generation of monodispersed and biocompatible NPs under aqueous conditions, and surface coupling of functional groups with a high efficiency.…”

A Divide-and-Conquer Strategy for Quantification of Light Absorption, Scattering, and Emission Properties of Fluorescent Nanomaterials in Solutions

“…Nanoscale fluorescent materials have become increasingly interesting for their applications in optical sensing, imaging, optoelectronics, energy harvesting, and photocatalytic reactions. − Understanding the optical properties of fluorescent nanomaterials is important for rational material design and applications. However, reliable quantifications of fluorophore photon absorption, scattering, and fluorescence activities can be challenging due to the complex interplay of the photon absorption, scattering, and emission.…”