title: Straightforward Micropatterning of Oligonucleotides in Microfluidics by Novel Spin-On ZrO₂ Surfaces.
abstract: DNA biochip assays often require immobilization of bioactive molecules on solid surfaces. A simple biofunctionalization protocol and precise spatial binding represent the two major challenges in order to obtain localized region specific biopatterns into lab-on-a-chip (LOC) systems. In this work, a simple strategy to anchor oligonucleotides on microstructured areas and integrate the biomolecules patterns within microfluidic channels is reported. A photosensitive ZrO2 system is proposed as an advanced platform and versatile interface for specific positioning and oriented immobilization of phosphorylated DNA. ZrO2 sol-gel structures were easily produced on fused silica by direct UV lithography, allowing a simple and fast patterning process with different geometries. A thermal treatment at 800 °C was performed to crystallize the structures and maximize the affinity of DNA to ZrO2. Fluorescent DNA strands were selectively immobilized on the crystalline patterns inside polydimethylsiloxane (PDMS) microchannels, allowing high specificity and rapid hybridization kinetics. Hybridization tests confirmed the correct probe anchoring and the bioactivity retention, while denaturation experiments demonstrated the possibility of regenerating the surface.
authors.affiliation: †Department of Industrial Engineering, University of Padova, Via Marzolo 9, 35131 Padova, Italy.|‡National Interuniversity Consortium of Materials Science and Technology (INSTM), Padova Research Unit, Via Marzolo 9, 35131 Padova, Italy.
authors.forename: Gioia
authors.initials: G
authors.lastname: Della Giustina
authors.affiliation: †Department of Industrial Engineering, University of Padova, Via Marzolo 9, 35131 Padova, Italy.|§Venetian Institute of Molecular Medicine (VIMM), Via Orus 2, 35129 Padova, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Zambon
authors.affiliation: †Department of Industrial Engineering, University of Padova, Via Marzolo 9, 35131 Padova, Italy.|‡National Interuniversity Consortium of Materials Science and Technology (INSTM), Padova Research Unit, Via Marzolo 9, 35131 Padova, Italy.|§Venetian Institute of Molecular Medicine (VIMM), Via Orus 2, 35129 Padova, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Lamberti
authors.affiliation: †Department of Industrial Engineering, University of Padova, Via Marzolo 9, 35131 Padova, Italy.|‡National Interuniversity Consortium of Materials Science and Technology (INSTM), Padova Research Unit, Via Marzolo 9, 35131 Padova, Italy.|§Venetian Institute of Molecular Medicine (VIMM), Via Orus 2, 35129 Padova, Italy.
authors.forename: Nicola
authors.initials: N
authors.lastname: Elvassore
authors.affiliation: †Department of Industrial Engineering, University of Padova, Via Marzolo 9, 35131 Padova, Italy.|‡National Interuniversity Consortium of Materials Science and Technology (INSTM), Padova Research Unit, Via Marzolo 9, 35131 Padova, Italy.
authors.forename: Giovanna
authors.initials: G
authors.lastname: Brusatin
mesh_terms: D061925:Immobilized Nucleic Acids / Q000737:chemistry*; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation* / Q000379:methods*; D036103:Nanotechnology; D013499:Surface Properties; D015040:Zirconium / Q000737:chemistry*
chemical_list: D061925:Immobilized Nucleic Acids; D015040:Zirconium; C028541:zirconium oxide
keywords: DNA functionalization; hybrid material; microfluidic; optical lithography; sol−gel