title: Precisely controlled smart polymer scaffold for nanoscale manipulation of biomolecules.
abstract: We demonstrate the application of a novel smart surface to modulate the orientation of immobilized double stranded DNA (dsDNA) and the conformation of a polymer scaffold through variation in buffer pH and ionic strength. An amphoteric poly(dimethylacrylamide) based coating containing weak acrylamido acids and bases, which are copolymerized together with the neutral monomer, is covalently bound to the surface. The coating can be made to contain any desired amount of buffering and titrant ionogenic monomers, allowing control of the surface charge when the surface is bathed in a given buffer pH. Spectral self-interference fluorescence microscopy (SSFM) is utilized to precisely quantify both the DNA orientation and the polymer conformation with subnanometer resolution. It is possible to utilize the polymer scaffold to functionalize a variety of common materials used in microfabrication, making it a general purpose building block for the next generation of nanomachines and biosensors.
authors.affiliation: Department of Biomedical Engineering, Boston University, Boston, Massachusetts 02215, USA.
authors.forename: Philipp S
authors.initials: PS
authors.lastname: Spuhler
authors.forename: Laura
authors.initials: L
authors.lastname: Sola
authors.forename: Xirui
authors.initials: X
authors.lastname: Zhang
authors.forename: Margo R
authors.initials: MR
authors.lastname: Monroe
authors.forename: Joseph T
authors.initials: JT
authors.lastname: Greenspun
authors.forename: Marcella
authors.initials: M
authors.lastname: Chiari
authors.forename: M Selim
authors.initials: MS
authors.lastname: Ünlü
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D015342:DNA Probes / Q000737:chemistry*; D008856:Microscopy, Fluorescence / Q000379:methods; D036103:Nanotechnology / Q000379:methods*; D011108:Polymers / Q000737:chemistry*
chemical_list: D015342:DNA Probes; D011108:Polymers