Layer-by-layer functionalized nanotube arrays: A versatile microfluidic platform for biodetection

Abstract

We demonstrate the layer-by-layer (LbL) assembly of polyelectrolyte multilayers (PEM) on three-dimensional nanofiber scaffolds. High porosity (99%) aligned carbon nanotube (CNT) arrays are photolithographically patterned into elements that act as textured scaffolds for the creation of functionally coated (nano)porous materials. Nanometer-scale bilayers of poly(allylamine hydrochloride)/poly(styrene sulfonate) (PAH/SPS) are formed conformally on the individual nanotubes by repeated deposition from aqueous solution in microfluidic channels. Computational and experimental results show that the LbL deposition is dominated by the diffusive transport of the polymeric constituents, and we use this understanding to demonstrate spatial tailoring on the patterned nanoporous elements. A proof-of-principle application, microfluidic bioparticle capture using N-hydroxysuccinimide-biotin binding for the isolation of prostate-specific antigen (PSA), is demonstrated.

Progress in Microfluidics‐Based Exosome Separation and Detection Technologies for Diagnostic Applications

“…Because of the merits of microfluidics, for example, high‐throughput capacity and low‐time requirements, microfluidics‐based devices are able to handle and analyze more/multiple samples in less time than conventional methods . Currently, microfluidic chips are widely applied in the separation and detection of micro/nanoparticles, biomarkers, cells, and proteins . A study conducted by Lin et al utilized a flyover microfluidic chip to separate white blood cells (WBCs) from mouse peripheral blood through a two‐stage magnetic separation methods ( Figure A) .…”

Carbon nanotubes in microfluidic lab-on-a-chip technology: current trends and future perspectives

“…Their work provided a promising platform for tailoring and grading of nanoporous scaffolds for LOC applications. Additionally, detection of prostate-specific antigen was demonstrated which used this platform (Yost et al 2015). …”

“…So, most of the techniques are not yet cost-effective for mass production of CNTs. Additionally, due to the difficulties that could occur during processes for immobilizing enzymes on the surface of CNTs, leading to damage occurring to enzymatic molecules, and reductions in bio-activity, biocompatibility and chemical stability (Yang et al 2015). Another limiting factor for wider use of CNTs could be their toxicity, which is discussed in detail in the next section.…”

Integration and Bio-Functionalization of Vertically Aligned Carbon Nanotube Forests on High Frequency AlN Gravimetric Sensors

“…In order to ensure the proper functionalization of the hydrophobic inner side of the forest, the side walls of each tube need to become hydrophilic, which we achieve following a specific protocol [7]. First, we incubate the devices with the anionic surfactant sodium dodecyl benzene sulfonate (SDBS).…”