Towards Nanowriting on Plastics: Dip‐Pen Nanolithography of Acrylamido‐Functionalized Oligonucleotides on Polystyrene

Abstract

Model high density DNA arrays have been realized by direct deposition with Dip-Pen Nanolithography of acrylamido-functionalized oligonucleotides (23-mer) on spin-coated, flat polystyrene surfaces. A highly specific interaction between the acrylamide end functionality and polystyrene was found. The surface morphology of the model array was studied by atomic force microscopy (AFM). Spots are clearly seen both in topography and demodulation modes. The array withstands the hybridization process with label free, complementary oligonucleotides and the following cleaning procedures. The final AFM characterization showed significant changes especially in demodulation images which may be an indication that molecular recognition between complementary oligos has occurred.

Highly Transparent Cyclic Olefin Copolymer Film with a Nanotextured Surface Prepared by One-Step Photografting for High-Density DNA Immobilization

“…Biochips, which capture a high density of biomolecule microarrays on their surfaces, have been one of the most powerful tools in various biorelated fields, including disease diagnostics, drug screening, genomics, and proteomics because of their fast, selective, sensitive, and high-throughput detection of target molecules. − Compared with the most commonly used glass substrates in biochip technology, many polymer materials also possess satisfactory optical transparency and suitable bulk rigidity in slide form for standard measurement. Moreover, thermoplastic polymers commonly have excellent processability and, thus, are amenable to large-scale production and can be microfabricated in a cost-effective manner for further integration with lab-on-a-chip devices. − Recently, some polymers have been intensively investigated as promising supports for preparation of biomolecule microarrays. − Among them, the cyclic olefin copolymer (COC) has attracted special interest because of its unique features of high transparency, low autofluorescence, good chemical resistance, and low water uptake under moist conditions. − However, the surface of the COC mainly consists of C–H bonds, which lack reactive sites for further covalent immobilization of biomolecules. Several techniques have been explored to overcome the surface inertness of the COC by introducing functional groups on its surface, including plasma treatment, UV/ozone oxidation, , adsorption of functional polymers by hydrophobic interaction, plasma-enhanced chemical vapor deposition, UV-photografting, and catalytic chemical oxidation. , Although these methods can effectively activate the COC surface with functional groups (e.g., COOH, OH, and NH 2 ) or a reactive polymer brush, they focus little on improving the sensitivity of the biochips.…”