Multiple Zones Modification of Open Off-Stoichiometry Thiol-Ene Microchannel by Aptamers: A Methodological Study & A Proof of Concept

Abstract

Off-stoichiometry thiol-ene polymer (OSTE) is an emerging thermoset with interesting properties for the development of lab-on-a-chip (LOAC), such as easy microfabrication process, suitable surface chemistry for modification and UV-transparency. One of the challenges for LOAC development is the integration of all the analytical steps in one microchannel, and particularly, trace level analytes extraction/preconcentration steps. In this study, two strategies for the immobilization of efficient tools for this purpose, thiol-modified (C3-SH) aptamers, on OSTE polymer surfaces were developed and compared. The first approach relies on a direct UV-initiated click chemistry reaction to graft thiol-terminated aptamers on ene-terminated OSTE surfaces. The second strategy consists of the immobilization of thiol-terminated aptamers onto OSTE substrates covered by gold nanoparticles. The presence of an intermediate gold nanoparticle layer on OSTE has shown great interest in the efficient immobilization of aptamers, preserving their interaction with the target, and preventing non-specific adsorption. With this second innovative strategy, we proved, for the first time the concept of creating multiple functional zones for sample treatment in an open OSTE-microchannel thanks to the immobilization of aptamers in consecutive areas by the simple droplet deposition methodology. This methodological development allows further consideration of OSTE material for lab-on-a-chip designs, integrating multiple zones for sample pretreatment, based on molecular recognition by ligands, such as aptamers, in a specific zone of the microchannel and is adaptable to a large range of analytical applications for LOAC industrialization.

Off-Stoichiometry Thiol–Enes Polymers Containing Silane Groups for Advanced Packaging Technologies

“…[ 8 , 9 ]. In addition, aptamers [ 10 ] and various enzymes, such as xylanas [ 11 ], horseradish peroxidase [ 12 ], α-chymotrypsin [ 13 ], or glucose oxidase [ 14 , 15 ], can be immobilized on the polymer surface.…”

Off-Stoichiometry Thiol–Ene Polymers: Inclusion of Anchor Groups Using Allylsilanes

“…It is also possible to obtain polymers saturated with free thiol or vinyl groups. Such OSTE polymers can be easily modified using various functional compounds [ 25 , 26 , 27 , 28 , 29 ]. The obtained Young’s modulus and tensile strength values are close to the maximum values obtained for the OSTE-MS polymer, and they are equal to 1.7 GPa and 58 MPa, respectively [ 23 ].…”

Lung on a Chip Development from Off-Stoichiometry Thiol–Ene Polymer

“…The required dual curing of the material (UV followed by thermal) allows retaining the ease of fabrication seen in PDMS devices without compromising resolution [ 33 ]. Excess of thiol groups on the surface allows for easy modification of the OSTE surfaces either after UV polymerization or after thermal curing steps via the thiol and hydroxy chemistries, respectively [ 34 , 35 ]. After thermal polymerization, OSTE becomes hard and obtains its final material properties.…”