Hierarchically Ordered Nanopatterns for Spatial Control of Biomolecules

Abstract

The development and study of a benchtop, high-throughput, and inexpensive fabrication strategy to obtain hierarchical patterns of biomolecules with sub-50 nm resolution is presented. A diblock copolymer of polystyrene-b-poly(ethylene oxide), PS-b-PEO, is synthesized with biotin capping the PEO block and 4-bromostyrene copolymerized within the polystyrene block at 5 wt %. These two handles allow thin films of the block copolymer to be postfunctionalized with biotinylated biomolecules of interest and to obtain micropatterns of nanoscale-ordered films via photolithography. The design of this single polymer further allows access to two distinct superficial nanopatterns (lines and dots), where the PEO cylinders are oriented parallel or perpendicular to the substrate. Moreover, we present a strategy to obtain hierarchical mixed morphologies: a thin-film coating of cylinders both parallel and perpendicular to the substrate can be obtained by tuning the solvent annealing and irradiation conditions.

Microphase segregation and selective chain scission of poly(2‐methyl‐2‐oxazoline)‐block‐polystyrene

“…). During the irradiation, PMeOx was hypothesized to be degraded or released due to hydrolysis of the ester linkage in PMeOx ‐b‐ PS while PS is slightly crosslinked, which improving its fidelity upon subsequent processing . The thin films were then rinsed with acetic acid to remove the degraded byproducts of PMeOx and/or released PMeOx.…”

Tuning microdomain spacing with light using ortho‐nitrobenzyl‐linked triblock copolymers

“…It has been shown that regional annealing or deposition can provide good lateral variations in thin BCP films; however, these methods rely on the availability of sophisticated instrumentation . Chemical reactions of the BCP thin films were also investigated, such as photo‐crosslinking and hydrolysis, of one of the blocks . Although these reactions were shown to provide excellent spatial control over the morphologies, their general utility was limited.…”

Reactive block copolymers for patterned surface immobilization with sub-30 nm spacing

“…Only a handful of examples for this approach can be found so far. 33,37,38 For instance, Lynn and co-workers reported the patterning of a fluorescent amine on a BCP nanostructured surface of which one block was entirely made of a custom, functional amine-reactive monomer unit. 38 Our idea is that it would be a more versatile method to employ a well-studied phase-segregating BCP system and introduce a functional comonomer during the synthesis in an amount that is (i) sufficient for further functionalization, (ii) yet low enough to preserve the phase behavior of the original, non-functional system.…”

“…Although some studies showed that small changes in structures can alter the morphologies and nanodomain periodicities, 39,40 a few reports suggested that incorporation of a small percentage (<10%) of functionalities into or at the end of the polymer backbones does not influence the phase separation behavior to a considerable extent. 37,[41][42][43][44] During the course of our study, Wiesner, Estroff, and co-workers have used such an elegant and versatile approach with a well-known phase-separating polystyrene-b-polyethylene glycol scaffold (PS-b-PEG), where a significant amount of allyl glycidyl ether was introduced in the PEG block to provide allyl anchors for further thiol-ene-based functionalization. 45 Nevertheless, only one type of functionality was reported and, in fact, the polymerization method which was used, i.e., anionic polymerization, may limit the range of accessible functionalities.…”