Self-Assembled Monolayers with Molecular Gradients

  • Michael SchäferlingEmail author
  • Michael Riepl
  • Bo Liedberg
Part of the Integrated Analytical Systems book series (ANASYS)


In recent years, biosensors and sensor arrays have developed into very important analytical tools, which found applications in many fields such as pharmaceutical (high-throughput) screening, medical diagnosis, or industrial process control. One of the major challenges for material research is the preparation of appropriate sensor surfaces, providing an interface with a high sensitivity and selectivity toward a given analyte. This chapter discusses some straightforward and flexible approaches to study structure and/or composition-function relationships and response characteristics of polymeric and molecular sensor materials. The controlled continuous deposition of self-assembled monolayers (SAMs), e.g. of substituted thiols or silanes, paves the way for the generation of molecular gradients on solid surfaces. These are useful for the preparation of interfaces with spatially controlled chemical composition and/ or physical properties. These tools can help to improve the selectivity and specificity of surfaces for biosensors and biochips. They can also be utilized for the study of fundamental protein adsorption and exchange phenomena.


Molecular Imprint Polymer Gold Surface Mixed Monolayer PDMS Stamp Fluorescent Chemosensors 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


  1. 1.
    Potyrailo, R. A., Polymeric sensor materials: Toward an alliance of combinatorial and rational design tools?, Angew. Chem. Int. Ed. 2006, 45, 702–723CrossRefGoogle Scholar
  2. 2.
    Meier M. A. R.; Schubert, U. S., Combinatorial polymer research and high-throughput experimentation: powerful tools for the discovery and evaluation of new materials, J. Mater. Chem. 2004, 14, 3289–3299CrossRefGoogle Scholar
  3. 3.
    Kohn, J. A., New approaches to biomaterials design, Nat. Mater. 2004, 3, 745–747CrossRefGoogle Scholar
  4. 4.
    Menger, F. M.; Eliseev, A. V.; Migulin, V. A., Phosphatase catalysis developed via combinatorial organic chemistry, J. Org. Chem. 1995, 60, 6666–6667CrossRefGoogle Scholar
  5. 5.
    Diaz-Garcia, M. E.; Pina-Luis, G.; Rivero, I., Combinatorial solid-phase organic synthesis for developing materials with molecular recognition properties, Trends Anal. Chem. 2006, 25, 112–121CrossRefGoogle Scholar
  6. 6.
    Wu, X.; Kim, J.; Dordick, J. S., Biotechnol. Prog. 2000, 10, 513–516CrossRefGoogle Scholar
  7. 7.
    Portyrailo, R. A.; May, R. J.; Sivavec, T. M., Sens. Lett. 2, 2004, 31–36CrossRefGoogle Scholar
  8. 8.
    Hierlemann, A.; Zellers, E. T.; Ricco, A. J., Anal. Chem. 2001, 73, 3458–3466CrossRefGoogle Scholar
  9. 9.
    Mirsky, V. M.; Kulikov, V.; Hao, Q.; Wolfbeis, O. S., Multiparameter high throughput characterization of combinatorial chemical microarrays of chemosensitive polymers, Macromol. Rapid Comm. 2004, 25, 253–258CrossRefGoogle Scholar
  10. 10.
    Batra, D.; Shea, K. J., Curr. Opin. Chem. Biol. 2003, 7, 434CrossRefGoogle Scholar
  11. 11.
    Liedberg, B.; Cooper, J., Bioanalytical applications of self-assembled monolayers, In Immobilized Biomolecules in Analysis: A practical approach; Cass, T.; Liegler, F. S., Eds.; PAS series, Oxford University Press, Oxford 1998Google Scholar
  12. 12.
    Ulman A., An Introduction to Ultrathin Organic Films, Academic, San Diego, CA 1991Google Scholar
  13. 13.
    Ulman A, Formation and structure of self-assembled monolayers, Chem. Rev. 1996, 96, 1533–1554CrossRefGoogle Scholar
  14. 14.
    Schäferling, M.; Kambhampati, D., Protein microarray surface chemistry and coupling schemes, In Protein Microarray Technology; Kambhampati D., Ed.; Wiley, Weinheim 2004Google Scholar
  15. 15.
    Schäferling, M.; Schiller, S.; Paul, H.; Kruschina, M.; Pavlickova P.; Meerkamp, M.; Giammasi, C.; Kambhampati, D., Application of self-assembly techniques in the design of biocompatible protein microarray surfaces, Electrophoresis, 2002, 23, 3097–3105CrossRefGoogle Scholar
  16. 16.
    Crego-Calama, M.; Reinhoudt, D. N., New materials for metal ion sensing by self-assembled monolayers on glass, Adv. Mater. 2001, 13, 1171–1174CrossRefGoogle Scholar
  17. 17.
    Basabe-Desmonts, L.; Beld, J.; Zimmerman, R. S.; Hernando, J.; Mela, P.; Garcia Parajo, M. F.; van Hulst, N. F.; van den Berg, A.; Reinhoudt, D. N., A simple approach to sensor discovery and fabrication on self-assembled monolayers on glass, J. Am. Chem. Soc. 2004, 126, 7293–7299CrossRefGoogle Scholar
  18. 18.
    Basabe-Desmonts, L.; Zimmerman, R. S.; Reinhoudt, D. N.; Crego-Calama, M., Combinatorial method for surface-confined sensor design and fabrication, In Springer Series on Chemical Sensors and Biosensors Vol. 3: Frontiers in Chemical Sensors; Orellana, G.; Moreno-Bondi, M.C., (Eds.); Springer, Berlin 2005Google Scholar
  19. 19.
    Liedberg, B.; Tengvall, P., Molecular gradients of ド-substituted alkanethiols on gold: preparation and characterization, Langmuir 1995, 11, 3821–3827CrossRefGoogle Scholar
  20. 20.
    McKenna, M. P.; Raper, J. A., Growth cone behavior on gradients of substratum bound laminin, Develop. Biol. 1988, 130, 232–236CrossRefGoogle Scholar
  21. 21.
    Halfter, W., The behavior of optic axons on substrate gradients of retinal basal lamina proteins and merosin, J. Neurosci. 1996, 16, 4389–4401Google Scholar
  22. 22.
    Bailly, M.; Yan, L.; Whitesides, G. M.; Condeelis, J. S.; Segall, J. E., Regulation of protrusion shape and adhesion to the substratum during chemotactic responses of mammalian carcinoma cells, Exp. Cell Res. 1998, 241, 285–299CrossRefGoogle Scholar
  23. 23.
    Baier, H.; Bonhoeffer F., Axon guidance by gradients of a target-derived component, Science 1992, 255, 472–475CrossRefGoogle Scholar
  24. 24.
    Bjellqvist, B.; Ek, K.; Righetti, P. G.; Gianazza, E.; Görg, A.; Westermeier, R.; Postel, W., Isoelectric focusing in immobilized pH gradients: Principle, methodology and some applications, J. Biochem. Biophys. Methods 1982, 6, 317–339CrossRefGoogle Scholar
  25. 25.
    Görg, A.; Postel, W.; Günther, S., The current state of two-dimensional electrophoresis with immobilized pH gradients, Electrophoresis 1988, 9, 531–546CrossRefGoogle Scholar
  26. 26.
    Groves, J. T.; Boxer, S. G., Electric field-induced concentration gradients in planar supported bilayers, Biophys. J. 1995, 69, 1972–1975CrossRefGoogle Scholar
  27. 27.
    Matyjaszewski, K.; Ziegler, M. J.; Arehart, S. V.; Greszta, D.; Pakula, T., Gradient copolymers by atom transfer radical copolymerization, J. Phys. Org. Chem. 2000, 13, 775–786CrossRefGoogle Scholar
  28. 28.
    Bhat, R. R.; Tomlinson, M. R.; Wu, T.; Genzer, J., Surface-grafted polymer gradients: formation, characterization, and applications, Adv. Polym. Sci. 2006, 198, 51–124CrossRefGoogle Scholar
  29. 29.
    Shen, M.; Bever, M. B., Gradients in polymeric materials, J. Mater. Sci. 1972, 7, 741–746CrossRefGoogle Scholar
  30. 30.
    Gölander, C. G.; Pitt, W. G., Characterization of hydrophobicity gradients prepared by means of radio frequency plasma discharge, Biomaterials 1990, 11, 32–35CrossRefGoogle Scholar
  31. 31.
    Wu, T.; Efimenko, K.; Vicek, P.; Subr, V.; Genzer, J., Formation and properties of anchored polymers with a gradual variation of grafting densities on flat substrates, Macromolecules 2003, 36, 2448–2453CrossRefGoogle Scholar
  32. 32.
    Askadskii, A. A., Development and properties of gradient polymeric materials, Russian Polym. News 1999, 4, 34–37Google Scholar
  33. 33.
    Pitt, W. G. Fabrication of a continous wettability gradient by radio frequency plasma discharge, J. Colloid Interface Sci. 1989, 133, 223–237CrossRefGoogle Scholar
  34. 34.
    Bhat, R. R.; Tomlinson, M. R.; Genzer, J., Orthogonal surface-grafted polymer gradients: A versatile combinatorial platform, J. Polym. Sci. B 2005, 43, 3384–3394CrossRefGoogle Scholar
  35. 35.
    Gersten, D. M.; Bijwaard, K. E., Polyacrylamide gel electrophoresis in vertical, inverse and double-crossing gradients of soluble polymers, Electrophoresis 1992, 13, 282–286CrossRefGoogle Scholar
  36. 36.
    Kryszewski, M., Gradient polymers and copolymers, Polym. Adv. Technol. 1998, 9, 244–259CrossRefGoogle Scholar
  37. 37.
    Le Grange, J. D.; Markham, J. L.; Kurjian, C. R., Effects of surface hydration on the deposition of silane monolayers on silica, Langmuir 1993, 9, 1749–1753CrossRefGoogle Scholar
  38. 38.
    Zammatteo, N.; Jeanmart, L.; Hamels, S.; Courtois, S.; Louette, P.; Hevesi, L.; Remacle, J., Comparison between different strategies of covalent attachment of DNA to glass surfaces to build DNA microarrays, Anal. Biochem. 2000, 280, 143–150CrossRefGoogle Scholar
  39. 39.
    Sullivan, T. P.; Huck, W. T., Reactions on monolayers: Organic synthesis in two dimensions, Eur. J. Org. Chem. 2003, 17–29Google Scholar
  40. 40.
    Onclin, S.; Ravoo, B. J.; Reinhoudt, D., Engineering silicon oxide surfaces using self-assembled monolayers, Angew. Chem. Int. Ed. 2005, 44, 6282–6304CrossRefGoogle Scholar
  41. 41.
    Lee, J. P.; Jang, Y. J.; Sung, M. M., Aomic layer deposition of TiO2 thin films on mixed self-assembled monolayers studied as a function of surface free energy, Adv. Funct. Mater. 2003, 13, 873–876CrossRefGoogle Scholar
  42. 42.
    Wasserman, S. R.; Tao, Y. T.; Whitesides, G. M., Structure and reactivity of alkylsiloxane monolayers formed by reaction of alkyltrichlorosilanes on silicon substrates, Langmuir 1989, 4, 1074–1087CrossRefGoogle Scholar
  43. 43.
    Mathauer, K.; Frank, C. W., Naphthalene chromophore tethered in the constrained environment of a self-assembled monolayer, Langmuir 1993, 9, 3002–3008CrossRefGoogle Scholar
  44. 44.
    Mathauer, K.; Frank, C. W., Binary self-assembled monolayers as prepared by successive adsorption of alkyltrichlorosilanes, Langmuir 1993, 9, 3446–3451CrossRefGoogle Scholar
  45. 45.
    Fadeev, A. Y.; McCarthy, T. J., Binary monolayer mixtures: modification of nanopores in silicon-supported tris(trimethylsiloxy)silyl monolayers, Langmuir 1999, 15, 7238–7243CrossRefGoogle Scholar
  46. 46.
    Fan, F.; Maldarelli, C.; Couzis, A., Fabrication of surfaces with nanoislands of chemical functionality by the phase separation of self-assembling monolayers on silicon, Langmuir 2003, 19, 3254–3265CrossRefGoogle Scholar
  47. 47.
    Finnie, K. R.; Nuzzo, R. G., The phase behavior of multicomponent self-assembled monolayers directs the nanoscale texturing of Si(100) by wet etching, Langmuir 2001, 17, 1250–1254CrossRefGoogle Scholar
  48. 48.
    Elwing, H.; Welin, S.; Askendal A.; Nilsson U.; Lundström, I., A wettability gradient method for studies of macromolecular interactions at the liquid/solid interface, J. Colloid Interface Sci. 1987, 119, 203–210CrossRefGoogle Scholar
  49. 49.
    Elwing, H.; Askendal, A.; Lundström, I., Competition between adsorbed fibrinogen and high-molecular weight kiniogen on solid surfaces incubated in human plasma (the Vroman effect): influence of solid surface wettability, J. Biomed. Mat. Res. 1987, 21, 1023–1028CrossRefGoogle Scholar
  50. 50.
    Elwing, H.; Askendal A.; Lundström I., Desorption of fibrinogen and gamma-globulin from solid surfaces induced by a nonionic detergent, J. Colloid Interface Sci. 1989, 128, 296–300CrossRefGoogle Scholar
  51. 51.
    Welin-Klintström, S.; Askendal, A.; Elwing, H., Surfactant and protein interactions on wettability gradient surfaces, J. Colloid Interface Sci. 1993, 158, 188–194CrossRefGoogle Scholar
  52. 52.
    Gölander, C.-G.; Lin, Y.-S.; Hlady, V.; Andrade, J. D., Wetting and plasma-protein adsorption studies using surfaces with a hydrophobicity gradient, Colloid Surf. 1990, 49, 289–302CrossRefGoogle Scholar
  53. 53.
    Gölander, C.-G.; Caldwell, K.; Lin, Y.-S., A new technique to prepare gradient surfaces using density gradient solutions, Colloid Surf. 1989, 42, 165–172CrossRefGoogle Scholar
  54. 54.
    Elwing, H.; Gölander, C.-G., Protein and detergent interaction phenomena on solid surfaces with gradients in chemical composition, Adv. Colloid Interface Sci. 1990, 32, 317–339CrossRefGoogle Scholar
  55. 55.
    Lin, Y.-S.; Hlady, V., Human serum albumin adsorption onto octadecyl-dimethylsilyl-silica gradient surface, Colloids Surf. B: Biointerfaces 1994, 2, 481–491CrossRefGoogle Scholar
  56. 56.
    Lin, Y.-S.; Hlady, V.; Gölander, C.-G., The surface density gradient of grafted poly(ethylene glycol): preparation, characterization and protein adsorption, Colloids Surf. B: Biointerfaces 1994, 3, 49–62CrossRefGoogle Scholar
  57. 57.
    Chaudhury, M. K.; Whitesides, G. M., How to make water run uphill, Science 1992, 256, 1539–1541CrossRefGoogle Scholar
  58. 58.
    Wu, T.; Efimenko, K.; Genzer, J., Combinatorial study of the mushroom-to-brush crossover in surface anchored polyacrylamide, J. Am. Chem. Soc. 2002, 124, 9394–9395CrossRefGoogle Scholar
  59. 59.
    Wu, T.; Efimenko, K.; Vlcek P., Subr, V., Genzer, J. Formation and properties of anchored polymers with a gradual variation of grafting densities on flat substrates, Macromolecules 2003, 36, 2448–2453CrossRefGoogle Scholar
  60. 60.
    Wu, T.; Gong, P.; Szleifer, I.; Vlcek, P.; Subr V.; Grenzer, J., Behavior of surface-anchored poly(acrylic acid) brushes with grafting density gradients on solid substrates: 1. experiment, Macromolecules 2007, 40, 8756–8764CrossRefGoogle Scholar
  61. 61.
    Zhoa, B., A combinatorial approach to study solvent-induced self-assembly of mixed poly (methyl methacrylate)/polystyrene brushes on planar silica substrates: effect of relative grafting density, Langmuir 2004, 20, 11748–11755CrossRefGoogle Scholar
  62. 62.
    Roberson, S. V.; Fahey, A. J.; Sehgal, A.; Karim, A., Multifunctional ToF-SIMS: combinatorial mapping of gradient energy substrates, Appl. Surf. Sci. 2002, 200, 150–164CrossRefGoogle Scholar
  63. 63.
    Fasolka, M. J.; Julthongpiput, D.; Briggman, K. A., Gradient reference surfaces for scanning probe microscopy, PMSE 2004, 90, 721Google Scholar
  64. 64.
  65. 65.
    Julthongpiput, D.; Fasolka, M. J.; Zhang, W.; Nguyen, T.; Amis, E. J., Gradient chemical micropatterns: a reference substrate for surface nanometrology, Nano Lett. 2005, 5, 1535–1540CrossRefGoogle Scholar
  66. 66.
    Venkateswar, R. A.; Branch, D. W.; Wheeler, B. C., An electrophoretic method for microstamping biomolecule gradients, Biomed. Microdevices 2000, 2, 255–264CrossRefGoogle Scholar
  67. 67.
    Kumar, A.; Whitesides, G. M., Features of gold having micrometer to centimeter dimensions can be formed through a combination of stamping with an elastomeric stamp and an alkanethiol “ink” followed by chemical etching, Appl. Phys. Lett. 1993, 63, 2002–2004CrossRefGoogle Scholar
  68. 68.
    Wilbur, J.L.; Kumar, A.; Kim E.; Whitesides, G. M., Microfabrication by microcontact printing of self-assembled monolayers, Adv. Mater. 1994, 6, 600–604CrossRefGoogle Scholar
  69. 69.
    Libioulle, L.; Bietsch, A.; Schmid, H.; Michel, B.; Delamarche, E., Contact-inking stamps for microcontact printing of alkanethiols on gold, Langmuir 1999, 15, 300–304CrossRefGoogle Scholar
  70. 70.
    Nuzzo, R. G.; Allara, D. L., Adsorption of bifunctional organic disulfides on gold surfaces, J. Am. Chem. Soc. 1983, 105, 4481–4483CrossRefGoogle Scholar
  71. 71.
    Porter, M. D.; Bright T. B.; Allara, D. L.; Chidsey, C. E. D., Spontaneously organized molecular assemblies. 4. Structural characterization of n-alkyl thiol monolayers on gold by optical ellipsometry, infrared spectroscopy, and electrochemistry, J. Am. Chem. Soc. 1987, 109, 3559–3568CrossRefGoogle Scholar
  72. 72.
    Bain, C. D.; Whitesides G. M., Correlations between wettability and structure in monolayers of alkanethiols adsorbed on gold, J. Am. Chem. Soc. 1988, 110, 3665–3666CrossRefGoogle Scholar
  73. 73.
    Kumar, A.; Biebuyck H. A.; Whitesides, G. M., Patterning self-assembled monolayers: applications in material science, Langmuir 1994, 10, 1498–1511CrossRefGoogle Scholar
  74. 74.
    Schreiber, F., Structure and growth of self-assembling monolayers, Prog. Surf. Sci. 2000, 65, 151–256CrossRefGoogle Scholar
  75. 75.
    Roberts, C.; Chen, C. S.; Mrksich, M.; Martichonok V., Ingber, D. E.; Whitesides, G. M., Using mixed self-assembled monolayers presenting RGD and (EG)3OH groups to characterize long-term attachment of bovine capillary endothelial cells to surfaces, J. Am. Chem. Soc. 1998, 120, 6548–6555CrossRefGoogle Scholar
  76. 76.
    Knoll, W.; Liley, M.; Piscevic, D.; Spinke, J.; Tarlov, M. J., Supramolecular architectures for the functionalization of solid surfaces, Adv. Biophys. 1997, 34, 231–251CrossRefGoogle Scholar
  77. 77.
    Riepl, M.; Enander, K.; Liedberg, B.; Schäferling, M.; Kruschina, M.; Ortigao, F., Functionalized surfaces of mixed alkanethiols on gold as a platform for oligonucleotide microarrays, Langmuir 2002, 18, 7016–7023CrossRefGoogle Scholar
  78. 78.
    Riepl, M.; Östblom, M.; Lundström, I.; Svensson, S. C. T.; van der Gron, A. W. D.; Schäferling, M.; Liedberg, B., Molecular gradients: an efficient approach for optimizing the surface properties of biomaterials and biochips, Langmuir 2005, 21, 1042–1050CrossRefGoogle Scholar
  79. 79.
    Valiokas, R.; Svedhem, S.; Svensson, S. C. T.; Liedberg, B., Self-assembled monolayers of oligo(ethylene glycol)-terminated and amide group containing alkanethiolates on gold, Langmuir 1999, 15, 3390–3394CrossRefGoogle Scholar
  80. 80.
    Benesch, J.; Svedhem, S.; Svensson, S. C. T.; Valiokas, R.; Liedberg, B.; Tengvall, P., Protein adsorption to oligo(ethylene glycol) self-assembled monolayers: experiments with fibrinogen, heparinized plasma, and serum, J. Biomat. Sci. 2001, 12, 581–597CrossRefGoogle Scholar
  81. 81.
    Geissler, M.; Chalsani, P.; Cameron, N. S.; Veres, T., Patterning of chemical gradients with submicrometer resolution using edge-spreading lithography, Small 2006, 2, 760–765CrossRefGoogle Scholar
  82. 82.
    Mougin, K.; Ham, A. S.; Lawrance, M. B.; Fernandez, E. J.; Hiller, A. C., Construction of a tethered poly(ethylene glycol) surface gradient for studies of cell adhesion kinetics, Langmuir 2005, 21, 4809–4812CrossRefGoogle Scholar
  83. 83.
    Morgenthaler, S. M.; Lee, S.; Zürcher, S.; Spencer, N. D., A simple, reproducible approach to the preparation of surface-chemical gradients, Langmuir 2003, 19, 10459–10462CrossRefGoogle Scholar
  84. 84.
    Morgenthaler, S. M.; Lee, S.; Spencer, N. D., Submicrometer structure of surface-chemical gradients prepared by a two-step immersion method, Langmuir 2006, 22, 2706–2711CrossRefGoogle Scholar
  85. 85.
    Venkataraman, N. V.; Zürcher, S.; Spencer, N. D., Order and composition of methyl-carboxyl and methyl-hydroxyl surface-chemical gradients, Langmuir 2006, 22, 4184–4189CrossRefGoogle Scholar
  86. 86.
    Kraus, T.; Stutz, R.; Balmer, T. E.; Schmid, H.; Malaquin, L.; Spencer, N. D.; Wolf, H., Printing chemical gradients, Langmuir 2005, 21, 7796–7804CrossRefGoogle Scholar
  87. 87.
    Herbert, C. B.; McLernon, T. L.; Hypolite, C. L.; Adams, D. N.; Pikus, L.; Huang, C. C.; Fields, G. B.; Letourneau, P. C.; Distefano, M. D.; Hu, W.-S., Micropatterning gradients and controlling surface density of photoactivatable biomolecules on self-assembled monolayers of oligo(ethylene glycol) alkanethiolates, Chem. Biol. 1997, 4, 731–737CrossRefGoogle Scholar
  88. 88.
    Wang, Q.; Bohn, P.W., Surface composition gradients of immobilized cell signaling molecules. Epidermal growth factor on gold, Thin Solid Films 2006, 513, 338–346CrossRefGoogle Scholar
  89. 89.
    Wang, Q.; Jakubowski, J. A.; Sweedler, J. V.; Bohn, P. W., Quantitative submonolayer spatial mapping of Arg-Gly-Asp-containing peptide organo-mercaptan gradients on gold with matrix-assisted laser desorption/ionization mass spectrometry, Anal. Chem. 2004, 76, 1–8CrossRefGoogle Scholar
  90. 90.
    Plummer, S. T.; Bohn, P.W., Spatial dispersion in electrochemically generated surface composition gradients visualized with covalently bound fluorescent nanospheres, Langmuir, 2002, 18, 4142–4149CrossRefGoogle Scholar
  91. 91.
    Daniel, S.; Chaudhury, M. K.; Chen, J. C., Fast drop movements resulting from the phase change on a gradient surface, Science 2001, 291, 633–636CrossRefGoogle Scholar
  92. 92.
    Lestelius, M.; Engquist, I.; Tengvall, P.; Chaudhury, M. K.; Liedberg, B., Order/disorder gradients of n-alkanethiols on gold, Colloids Surf., B: Biointerfaces 1990, 15, 57–70CrossRefGoogle Scholar
  93. 93.
    Riepl, M.; Lundström, I.; Liedberg, B., New methods for the preparation of (bio)sensor surfaces: Molecular gradients and mixed monolayers containing oligo(ethylene glycols), Proceedings 2. Deutsches Biosensor-Symposium, Tübingen, Germany, 2001Google Scholar

Copyright information

© Springer Science + Business Media, LLC 2009

Authors and Affiliations

  • Michael Schäferling
    • 1
    Email author
  • Michael Riepl
    • 2
  • Bo Liedberg
    • 3
  1. 1.Institute of Analytical Chemistry, Chemo- and BiosensorsUniversity of RegensburgRegensburgGermany
  2. 2.Olympus Life Science Research Europa GmbHMunichGermany
  3. 3.University of Linköping, Division of Molecular Physics, Department of Physics, Chemistry and BiologyLinköping UniversityLinköpingSweden

Personalised recommendations