Authors: C. Zhou, K.De keersmaecker, D. Braeken, G. Reekmans, C. Bartic, H. De Smedt, Y. Engelborghs and G. Borghs
Affilation: Interuniversity Microelectronics Center (IMEC), Belgium
Pages: 750 - 753
Keywords: biosenoser, interface, protein adsorption, copolymer, poly(ethylene glycol)
The ability to control biomolecular interactions at the solid-liquid interface is essential for the development of high-performance biosensors. Conventional methods to tailor the surface properties of biosensors are based on Self-Assembled Monolayers (SAMs) and Surface Grafted Polymers (SGPs) each with its drawbacks: SAMs lack the 3-D nature and robustness of SGPs while the preparation of SGPs is not as easy nor reproducible as SAMs. To overcome these shortcomings, we have developed a Polymeric Monolayer (PM) - based on a water-soluble PEG-grafted polymer - that combines the advantages of SAMs with those of polymers. We demonstrate that the solvent from which the PM is deposited controls the organization of the PM and thereby can be used to tune the properties of the PM in interacting with proteins and cells. This relationship is substantiated by experimental data showing that: (a) a water-based PM with OCH3 functionalized PEG exhibits excellent protein resistance (<0.1ng/cm2), while (b) a water-based PM with COOH functionalized PEG makes an excellent immunosensor layer (for SPR) as it covalently binds a high amount of antibody, yielding a detection limit of < 1ng/ml antigen. Furthermore, the specific nature of our PM allows easy patterning through a combination of lift-off and self-assembly. This trait was exploited to spatially control protein adsorption and cell attachment. We believe that the solvent controlled self-assembly of our PM offers a simple and highly adaptable way to construct a high-performance biosensor interface.