Three-dimensional plasma micro–nanotextured cyclo-olefin-polymer surfaces for biomolecule immobilization and environmentally stable superhydrophobic and superoleophobic behavior Kosmas Ellinas a,1 , Katerina Tsougeni a,1 , Panagiota S. Petrou b , George Boulousis a , Dimitris Tsoukleris c , Evangelia Pavlatou c , Angeliki Tserepi a , Sotirios E. Kakabakos b , Evangelos Gogolides a,⇑ a Institute of Nanoscience and Nanotechnology, NCSR ‘‘Demokritos”, 153 10 Aghia Paraskevi, Attiki, Greece b Institute of Nuclear & Radiological Sciences & Technology, Energy & Safety, NCSR Demokritos, 15310 Aghia Paraskevi, Greece c School of Chemical Engineering, National Technical University of Athens, 9 Heroon, Polytechniou St., Zografos, 157 80 Athens, Greece highlights  Micro–nanotexturing of COP is done using plasma etching.  Chemically stable and high binding surfaces are demonstrated.  Alternatively, environmentally stable superoleophobic COP surfaces are fabricated.  COP functional surfaces with localized high binding/antifouling patterns. graphical abstract S T O F P g n i l a e n n A Plasma micro- nanotextured COP High binding surfaces Superoleophobic surfaces article info Article history: Received 10 February 2016 Received in revised form 20 April 2016 Accepted 26 April 2016 Available online 27 April 2016 Keywords: Plasma micro–nanotexturing Biomolecule binding surfaces Covalent immobilization Environmentally stable superhydrophobicity Superoleophobicity abstract Cyclo-olefin polymer (COP) surfaces are micro–nanotextured using O 2 plasma chemistry in one-step pro- cess. These surfaces subsequently display multiple functionality, (A) they are stable in time (i.e. non age- ing), functional, high surface area, substrates suitable for biomolecule binding, after thermal annealing in order to induce accelerated hydrophobic recovery while preserving the chemical functionality created by the plasma. (B) Alternatively, they are robust and environmentally stable superhydrophobic and super- oleophobic surfaces, after mechanical stabilization via wetting–drying and gas-phase coating with a per- fluoroctyltrichlorosilane monolayer (PFOTS) or plasma deposited Teflon-like polymer layer. The plasma treated, micro–nanotextured surfaces used for biomolecule binding exhibit remarkable retention of the initially immobilized biomolecule compared to untreated COP surfaces (up to 75%), after washing with aggressive washing solutions (sodium dodecyl sulfate), while showing excellent intensity, uniformity and sensitivity. The superoleophobic COP material surfaces exhibit very high static contact angles (SCA >150°) and very low hysteresis (CAH <10°), for a wide range of liquids from water (surface tension: 72.8 mN/m) to hexadecane (surface tension: 27 mN/m). In addition, these superhydrophobic and super- oleophobic surfaces exhibit excellent stability against environmental ageing after 60 continuous cycles of exposure to various harsh environmental conditions (heat, moisture, UV irradiation) in a controlled envi- ronment. Finally, the two presented functionalities are combined for the first time on the same COP sub- strate, creating localized rough hydrophilic and antifouling patterns that exhibit spatially selective biomolecule immobilization inside a microfluidic device. Ó 2016 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.cej.2016.04.137 1385-8947/Ó 2016 Elsevier B.V. All rights reserved. ⇑ Corresponding author. E-mail address: e.gogolides@inn.demokritos.gr (E. Gogolides). 1 These authors contributed equally. Chemical Engineering Journal 300 (2016) 394–403 Contents lists available at ScienceDirect Chemical Engineering Journal journal homepage: www.elsevier.com/locate/cej