A-444. Adaptive PolCarr carriers for novel applications in life sciences. Heidemarie Schmidt

Transcription

1 A-444 Adaptive PolCarr carriers for novel applications in life sciences Heidemarie Schmidt Nano-Spintronics Group Department of Materials for Nanoelectronics Chemnitz University of Technology

2 Outlook Polarizable materials and electrostatic forces Charge-patterned silicon wafers Detection of surface-near electrostatic forces (SNEF) Carriers for nonlocal and local adsorption of polarizable materials PolCarr carriers for novel applications in life sciences Summary 2

3 Collaborations & Acknowledgments K. Wiesenhütter, I. Skorupa, U. Wiesenhütter, A. Kolitsch, W. Skorupa, J. Raff/ Helmholtz-Zentrum Dresden-Rossendorf O.G. Schmidt/ TU Chemnitz, IFW Dresden M. Rüb/ EAH Jena A.-D. Müller/ Anfatec Instruments AG J. Meyer, D. Teichmann, S. Friedrich-Löbelt, K. Rosenkranz, T. Förster/ Ascenion GmbH M. Müller, P. Uhlmann/ IPF Dresden A.-K. Meyer/ Klinik für Neurologie, TU Dresden J. Pahnke/ Section of Neuropathology, University of Oslo O. Deschaumes, C.Bartic/ Soft Matter and Biophysics, KU Leuven G. Ettenberger/ Pharma, Medizinprodukte und Hygiene, OFI Wien F.W. Falkenberg / CIRES GmbH 3

4 Polarizable materials and electrostatic forces

5 Polarizable materials with electric dipole p Molecule where electrons are concentrated in one place has instantaneous dipole p Molecule with two atoms with different electronegativity has permanent dipole p Molecule where electrons are repelled by permanent dipole of another molecule has induced dipole p Water molecule in vapour, p=1.85 D Cis isomer, p=1.90 D Trans isomer, p=0 D 5 5

6 Electrostatic forces F Charges create electric field E. Long-range ( nm) Coulomb force F between charges + - Dipole moment p tends to align in an electric field E p E No labeling of polarizable material needed. Many molecules and biomaterials are polarizable. 6

7 Electrostatic forces between molecules Attractive force - Repulsive force + + Anionic polymer Cationic polymer Cationic polymer Advances in Polymer Science 255 & 256 (Ed.: Martin Müller), Springer,

8 Charge-patterned silicon wafers 8

9 Small charge/area concentration Frictional electrostatic generator negative (-) charge on rasps positive (+) charge on glass plate Bottle battery consisting of 25 Leyden jars (inside (+) & outside (-) metal-coated glas) (Deutsches Museum München, Inv. Nr. 3920) Leyden jar (battery) Charges/area: e/m 2 1 e/(100 nm x100 nm) 9

10 Large charge/area concentration F F kv DANFYSIK 1090, High current ion implanter 500 kv ion implanter Length scale:1 mm - 1 mm - 1 nm Implanted silicon wafer Charges/area: e/m 2 1 e/(1 nm x1 nm) 10

11 Detection of surface-near electrostatic forces (SNEF) 11

12 Probing SNEF by KPFM Kelvin probe force microscopy (KPFM) Minimization of electrostatic forces acting on the cantilever (vibration amplitude f ac ) by applying the appropriate KPFM bias U K to the sample backside. Topography (resonance frequency f r, vibration amplitude ~10 nm) and KPFM bias U K (operation frequency f ac, vibration amplitude < 20 pm) probed simultaneously. 12

13 Probing SNEF by KPFM Minimization of the SNEF by accumulation of mobile majority charge carriers in the surface region of the doped semiconductor KPFM bias applied to sample backside is related with energy difference between Fermi energy E F and respective band edge [2] Picture: Sander Münster, Kunstkosmos Doped Si cantilevers (NSC15, k=46 N/m): f ac =5 khz-130 khz < f r =265 khz-400 khz C. Baumgart, M. Helm, H. Schmidt, Phys. Rev. B 80 (2009) 13

14 Carriers for nonlocal and local adsorption of polarizable materials: 3 Proof-of-Concept (PoC) 14

15 Nonlocal adsorption of polarizable material Carrier A: Si substrate with polyelectrolyte coating T.J. Günther, M. Suhr, J. Raff, K. Pollmann, Immobilization of microorganisms for AFM studies in liquids, RCS Adv. 4 (2014)

16 PoC with microorganisms on carrier A A Viridibacillus arvi JG-B58 B Lysinibacillus sphaericus JG-B53, OD 600 =0.05 C E.coli, OD 600 =0.10 D E.coli, OD 600 =0.05 OD 600 : optical density of cells in a 600 nm Successful immobilization for AFM studies in liquids T.J. Günther, M. Suhr, J. Raff, K. Pollmann, RCS Adv. 4 (2014) 16

17 Nonlocal adsorption of polarizable material Carrier B: Si cantilever with SiO 2 coating O. Bäumchen et al., Vom Photolack zum Gecko, Physik Journal 14 (2015)

18 Frequency in percent Frequency in percent PoC with bacteria on carrier B Hydrophilic surface Hydrophobic surface Adhesive power in nn Adhesive power in nn Force F increases with decreasing SiO 2 thickness O. Bäumchen et al., Vom Photolack zum Gecko, Physik Journal 14 (2015)

19 Local adsorption of polarizable material Carrier C: PolCarr carrier Charge-patterned silicon wafer Dipping/spin-coating in/of solution with polarizable material Local attachment of polarizable material on PolCarr carrier H. Schmidt, S. Habicht, S. Feste, A.-D. Müller, O.G. Schmidt, Appl. Surf. Sci. 281 (2013) 19

20 Local adsorption of polarizable material Diethylaminoethyl-Dextran-FITC (DEAE-FITC) (Ø=10-20 nm (ph=9), l=200 nm (ph=4)) Local P-implantation of n + -Si stripes (5 mm width, 15 mm periodicity) into n-si Dipping at ph=11 (1 mg/ml) ph=9 ph=4 Rinsing (5 min, dest. water) Drying (10 min, 50 C) Advances in Polymer Science 255 & 256 (Ed.: Martin Müller), Springer, 2014 H. Schmidt, S. Habicht, S. Feste, A.-D. Müller, O.G. Schmidt, Appl. Surf. Sci. 281 (2013) 20

21 Positively charged molecule (DEAE-FITC) Cationic polymer diethylaminoethyl-dextran-fitc (DEAE-FITC) + ph=9 ph=4 + Monomer molar mass: 231g/mol Polymer molar mass: g/mol Charges per monomer unit: 0.5 Branched topology, Labeled with Fluoresceinisothiocyanat/FITC Coiled chain (ph=9): Ø=10-20 nm Elongated chain (ph=4): l=200 nm Advances in Polymer Science 255 & 256 (Ed.: Martin Müller), Springer,

22 PoC with DEAE-FITC on carrier C 10 mm 100% coating of n + -Si-stripes with DEAE-FITC Standard Si wafer: <20% coating 22

23 PolCarr for novel applications in life sciences 23

24 Fabrication of PolCarr carriers Design of photolithography mask Selection of implantation parameters Ion implantation Dopant activation Deposition of biocompatible thin film 24

25 Microwell plates with PolCarr bottom plate 25

26 Microwell plates with PolCarr bottom plate Charge-pattern in PolCarr bottom plate (implanted Si wafer) for local attachment of polarizable biomaterials and for adherent cell growth is defined by implantation pattern and by species of implanted ions. 26

27 Summary Charges in implanted silicon wafers create SNEF SNEF probed by Kelvin probe force microscopy PolCarr carriers with SNEF pattern for local attachment of polarizable materials retaining functionality during: Autoclaving for sterilization (+121 C, high pressure steam, min) Incubation for cell growth (+37 C, ph, CO 2, O 2, N 2, hours-days) Cryogenic applications for shock freezing (-196 C, days-weeks-months) 27

28 Thank you for your attention. PD Dr. Heidemarie Schmidt Nano-Spintronics Group Department of Materials for Nanoelectronics Chemnitz University of Technology Phone: