title: Interrogating Surface Functional Group Heterogeneity of Activated Thermoplastics Using Super-Resolution Fluorescence Microscopy.
abstract: We present a novel approach for characterizing surfaces utilizing super-resolution fluorescence microscopy with subdiffraction limit spatial resolution. Thermoplastic surfaces were activated by UV/O3 or O2 plasma treatment under various conditions to generate pendant surface-confined carboxylic acids (-COOH). These surface functional groups were then labeled with a photoswitchable dye and interrogated using single-molecule, localization-based, super-resolution fluorescence microscopy to elucidate the surface heterogeneity of these functional groups across the activated surface. Data indicated nonuniform distributions of these functional groups for both COC and PMMA thermoplastics with the degree of heterogeneity being dose dependent. In addition, COC demonstrated relative higher surface density of functional groups compared to PMMA for both UV/O3 and O2 plasma treatment. The spatial distribution of -COOH groups secured from super-resolution imaging were used to simulate nonuniform patterns of electroosmotic flow in thermoplastic nanochannels. Simulations were compared to single-particle tracking of fluorescent nanoparticles within thermoplastic nanoslits to demonstrate the effects of surface functional group heterogeneity on the electrokinetic transport process.
authors.forename: Colleen E
authors.initials: CE
authors.lastname: ONeil
authors.forename: Joshua M
authors.initials: JM
authors.lastname: Jackson
authors.affiliation: Department of Biomedical Engineering, School of Life Sciences, Ulsan National Institute of Science and Technology (UNIST) , Ulsan, South Korea.
authors.forename: Sang-Hee
authors.initials: SH
authors.lastname: Shim
authors.affiliation: Department of Biomedical Engineering, School of Life Sciences, Ulsan National Institute of Science and Technology (UNIST) , Ulsan, South Korea.
authors.forename: Steven A
authors.initials: SA
authors.lastname: Soper
mesh_terms: D002232:Carbocyanines / Q000737:chemistry; D002264:Carboxylic Acids / Q000032:analysis* / Q000138:chemical synthesis; D004586:Electrophoresis; D005456:Fluorescent Dyes / Q000737:chemistry; D008856:Microscopy, Fluorescence / Q000379:methods*; D053758:Nanoparticles / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry; D010126:Ozone / Q000737:chemistry; D019904:Polymethyl Methacrylate / Q000737:chemistry*; D011137:Polystyrenes / Q000737:chemistry; D013499:Surface Properties; D014466:Ultraviolet Rays
chemical_list: C569686:Alexa Fluor 647; D002232:Carbocyanines; D002264:Carboxylic Acids; D005456:Fluorescent Dyes; D011137:Polystyrenes; D010126:Ozone; D019904:Polymethyl Methacrylate; D010100:Oxygen