Oligonucleotide Immobilization and Hybridization on Aldehyde-Functionalized Poly(2-hydroxyethyl methacrylate) Brushes

Abstract

DNA biosensing requires high oligonucleotide binding capacity interface chemistries that can be tuned to maximize probe presentation as well as hybridization efficiency. This contribution investigates the feasibility of aldehyde-functionalized poly(2-hydroxyethyl methacrylate) (PHEMA) brush-based interfaces for oligonucleotide binding and hybridization. These polymer brushes, which allow covalent immobilization of oligonucleotides, are prepared by surface-initiated atom transfer radical polymerization (SI-ATRP) of HEMA followed by a postpolymerization oxidation step to generate side chain aldehyde groups. A series of polymer brushes covering a range of film thicknesses and grafting densities was investigated with regard to their oligonucleotide binding capacity as well as their ability to support oligonucleotide hybridization. Densely grafted brushes were found to have probe oligonucleotide binding capacities of up to ∼30 pmol/cm(2). Increasing the thickness of these densely grafted brush films, however, resulted in a decrease in the oligonucleotide binding capacity. Less densely grafted brushes possess binding capacities of ∼10 pmol/cm(2), which did not significantly depend on film thickness. The oligonucleotide hybridization efficiencies, however, were highest (93%) on those brushes that present the lowest surface concentration of the probe oligonucleotide. These results highlight the importance of optimizing the probe oligonucleotide surface concentration and binding interface chemistry. The versatility and tunability of the PHEMA-based brushes presented herein makes these films a very attractive platform for the immobilization and hybridization of oligonucleotides.

New Aldehyde‐Functional Methacrylic Water‐Soluble Polymers

“…In the field of synthetic polymer chemistry, aldehyde‐based initiators [2–8] have been utilized to prepare various types of aldehyde‐functional polymers. Alternatively, Bilgic and Klok derivatized poly(2‐hydroxyethyl methacrylate) brushes under oxidative conditions in order to introduce aldehyde groups for subsequent oligonucleotide conjugation [9] . However, surprisingly few aldehyde‐functional monomers have been reported in the literature [10, 11, 12–25] .…”

New Aldehyde‐Functional Methacrylic Water‐Soluble Polymers

“…[1] In the field of synthetic polymer chemistry,a ldehyde-based initiators [2][3][4][5][6][7][8] have been utilized to prepare various types of aldehydefunctional polymers.A lternatively,B ilgic and Klok derivatized poly(2-hydroxyethyl methacrylate) brushes under oxidative conditions in order to introduce aldehyde groups for subsequent oligonucleotide conjugation. [9] However,s urprisingly few aldehyde-functional monomers have been reported in the literature. [10,11,[12][13][14][15][16][17][18][19][20][21][22][23][24][25] Most of these examples are hydro-phobic (e.g.4 -vinylbenzaldehyde) and hence produce waterinsoluble polymers.…”

Poly(glycidyl methacrylate-co-2-hydroxyethyl methacrylate) Brushes as Peptide/Protein Microarray Substrate for Improving Protein Binding and Functionality

“…Polymeric coating is a simple method for preparing 3D microarray substrates . Among these coatings, polymer brushes are attractive 3D substrates because the polymer brushes have several advantages including facile in situ synthesis, high biomolecule immobilization capacity, and accessible scaffolds with sufficient space for biomolecules binding. − For instance, aldehyde-functionalized poly­(2-hydroxyethyl methacrylate) (PHEMA) brushes were employed as platforms for the immobilization and hybridization of oligonucleotides . Then PHEMA brush nanocone arrays with various morphologies and periods were prepared as substrates for DNA detection, which are rapid, visible, and multiplex .…”

“…15−18 For instance, aldehyde-functionalized poly(2hydroxyethyl methacrylate) (PHEMA) brushes were employed as platforms for the immobilization and hybridization of oligonucleotides. 19 Then PHEMA brush nanocone arrays with various morphologies and periods were prepared as substrates for DNA detection, which are rapid, visible, and multiplex. 20 However, both the works require subsequent functionalization after polymerization.…”