title: Immobilization mechanisms of deoxyribonucleic acid (DNA) to hafnium dioxide (HfO2) surfaces for biosensing applications.
abstract: Immobilization of biomolecular probes to the sensing substrate is a critical step for biosensor fabrication. In this work we investigated the phosphate-dependent, oriented immobilization of DNA to hafnium dioxide surfaces for biosensing applications. Phosphate-dependent immobilization was confirmed on a wide range of hafnium oxide surfaces; however, a second interaction mode was observed on monoclinic hafnium dioxide. On the basis of previous materials studies on these films, DNA immobilization studies, and density functional theory (DFT) modeling, we propose that this secondary interaction is between the exposed nucleobases of single stranded DNA and the surface. The lattice spacing of monoclinic hafnium dioxide matches the base-to-base pitch of DNA. Monoclinic hafnium dioxide is advantageous for nanoelectronic applications, yet because of this secondary DNA immobilization mechanism, it could impede DNA hybridization or cause nonspecific surface intereactions. Nonetheless, DNA immobilization on polycrystalline and amorphous hafnium dioxide is predominately mediated by the terminal phosphate in an oriented manner which is desirable for biosensing applications.
authors.affiliation: College of Nanoscale Science and Engineering, University at Albany, SUNY, 257 Fuller Road, Albany, New York 12203, USA.
authors.forename: Nicholas M
authors.initials: NM
authors.lastname: Fahrenkopf
authors.forename: P Zachary
authors.initials: PZ
authors.lastname: Rice
authors.forename: Magnus
authors.initials: M
authors.lastname: Bergkvist
authors.forename: N Aaron
authors.initials: NA
authors.lastname: Deskins
authors.forename: Nathaniel C
authors.initials: NC
authors.lastname: Cady
mesh_terms: D015374:Biosensing Techniques; D004247:DNA / Q000032:analysis*; D006195:Hafnium / Q000737:chemistry*; D061925:Immobilized Nucleic Acids / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry; D009693:Nucleic Acid Hybridization; D010087:Oxides / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D061925:Immobilized Nucleic Acids; D010087:Oxides; C545179:hafnium oxide; D004247:DNA; D006195:Hafnium