Page Areas:



Additional Information:

Victoria Lunz - Genuinely Passionate about Research

Hier den Alternativtext zum Bild eingeben!

[February 2017] Photo credited to OÖ Nachrichten ...  more of Victoria Lunz - Genuinely Passionate about Research (Titel)

Tuning membrane protein mobility by confinement into nanodomains

Hier den Alternativtext zum Bild eingeben!

[2016/11/16] In cooperation with Prof. Peter Pohl (Institute of Biophysics, JKU), lead CBL researchers DI Andreas Karner and Dr. Johannes Preiner have developed a platform to study membrane proteins. ...  more of Tuning membrane protein mobility by confinement into nanodomains (Titel)

Linz Winter Workshop 2017

Hier den Alternativtext zum Bild eingeben!

3 to 6 February 2017 ...  more of Linz Winter Workshop 2017 (Titel)

Tiemann-Boege Awarded Pilgerstorferpreis

Hier den Alternativtext zum Bild eingeben!

[2016/07/07] Assoc. Prof. Dr. Irene Tiemann-Boege was awarded the Pilgerstorferpreis from the Medical Society of Upper Austria.

Heißl awarded ÖAW Doc Scholarship

Hier den Alternativtext zum Bild eingeben!

[2016/03/04] Angelika Heißl's 3-year DOC fellowship granted by the Austrian Acadamy of Sciences (ÖAW) started on the 1 January 2016. The title is: "Meiotic recombination as a potential driver of microsatellite evolution". ...  more of Heißl awarded ÖAW Doc Scholarship (Titel)

Cholesterol in the fight against allergies

Hier den Alternativtext zum Bild eingeben!

[2016/02/15] Cholesterol in the fight against allergies ...  more of Cholesterol in the fight against allergies (Titel)

Biophysics Researchers Discover New Immune Protein Structure

Hier den Alternativtext zum Bild eingeben!

[2016/02/05] Scientists at the JKU Institute for Biophysics (a working group under a. Univ. Prof. Christoph Romanin) have deciphered a key function in the “Orai1” immune protein. ...  more of Biophysics Researchers Discover New Immune Protein Structure (Titel)


Position Indication:

Content

Self-Assembled Monolayers (SAMs) on gold

Gold surfaces are particularly suited for immobilization of biomolecules on biosensor surfaces:

• Gold is chemically inert, thus it can be cleaned under harsh conditions which remove all contaminations. Moreover, gold stays clean for a few minutes under ambient conditions, in contrast to most other inorganic surfaces.

• Only thiols (R-SH) or disulfides (R-S-S-R) form covalent bonds with gold. As a consequence, linear molecules with a terminal thiol or disulfide form densely packed monolayers on gold surfaces. The stability of such a self-assembled monolayer (SAM) is additionally enhanced if the thiol or disulfide is attached to a long alkyl chain (n ≥ 11).

• SAMs from simple alkanethiols [HS-(CH2)n-CH3] are hydrophobic. The methyl group, however, can be replaced by functional groups (e.g. OH, COOH, NH2, etc.) which are polar and chemically reactive. Moreover, mixed SAMs with different functional groups can be formed, thus the chemical and physical properties of SAM surfaces can be fine-tuned as needed.

• SAMs with short polyethylene glycol (PEG, see Fig. 3) chains are repelling to proteins and nucleic acids. Such protein-resistant SAMs are needed for biosensor surfaces because any nonspecific adsorption of protein or nucleic acid would lead to a false-positive signal.

• SAMs with a defined area density of reactive groups are required for covalent immobilization of biomolecules in a number of applications:

o In a biosensor, the immobilized biomolecules (e.g. antibodies) serve as “baits” which capture complementary “prey” molecules (e.g. antigens) from the sample solution. Binding is detected by surface plasmon resonance (SPR, e.g. in a BIAcore® instrument) or by a quartz crystal microbalance (QCM).

o Biosensors are often used for Biological Interaction Analysis (BIA), with one of the interacting components being immobilized on a protein-resistant chip while the second component is offered from solution at different concentrations, and in the presence/absence of further regulatory components. In this way, the mechanism of biomolecular interactions can be analyzed.

o The single molecule version of BIA is recognition force spectroscopy in the atomic force microscope (AFM). Here, one of the interacting components is tethered to the AFM tip while the complementary component must be immobilized on an ultra-flat surface (see Fig. 1 in chapter 1). Freshly cleaved mica is unparalleled in flatness and cleanness, yet chemical derivatization is difficult [4]. A versatile alternative to mica is “template-stripped gold” which is first evaporated onto clean mica, and then stripped from the mica surface [Hegner et al. 1993, Surface Sci. 291, 39-46]. After stripping, the gold surface must be covered with a suitable SAM, before the biomolecules can be immobilized.

Our interest is to provide SAMs for studies of Biological Interaction, both in small ensembles (in the BIAcore), and on the single-molecular level (in the AFM). Our approach has been to create modular SAMs (chapters 2.2.–2.4.) which can be adapted to different immobilization problems (see chapter 2.3.). For a firm basis, we examined the preparation and durability of protein-resistant SAMs, with unexpected findings, as described in chapter 2.1.

WORK ON THIS PAGE IS STILL IN PROGRESS