Covalent Attachment of Bioactive Protein to Any Surface

Ref: 10132
This technology enables the robust attachment of biomolecules, including enzymes, antibodies, structural proteins and synthetic polypeptides, to any underlying material, retaining biological activity.

Key advantages
  • Enables covalent protein attachment on polymers, metals, semiconductors and ceramics
  • Easy attachment process directly from solution with no requirement for chemical linkers
  • Biological activity is retained over significantly longer periods than for most competing attachment methods
  • Plasma based process, easily adaptable for patterning and etching of substrates or the attachment interface layer

Background

Many modern applications in medicine, environmental sensing, and food and chemical processing utilise the biological activity of biomolecules and benefit from having them localised on a surface.

Examples include diagnostic arrays and biosensors, where antibodies or other biological molecules are attached at discrete locations on a substrate surface allowing the detection of their biorecognition of target molecules.

The development of such applications has led to an increased demand for surfaces capable of binding biological molecules such as antibodies, other proteins and nucleic acids.

An ideal surface for these applications should bind proteins or other biological molecules while preserving their function. The binding needs to be strong and stable over extended periods and resilient to repeated washing steps.

Currently available methods of immobilising protein molecules rely on either specially designed chemical linker molecules to achieve covalent attachment after a series of complex and time consuming wet chemical steps, or adsorption from solution due to physical interactions.

Physical adsorption has the disadvantage of being unreliable because its effectiveness is very sensitive to the properties of the protein and the surface.

The bioactivity is usually not stable over time because the many weak physical interactions required to achieve surface immobilisation often result in denaturation of the protein.

The invention

Top: Partial protein coverage on polystyrene. Bottom: Full coverage on our interface layer.

Top: Partial protein coverage on polystyrene. Bottom: Full coverage on our interface layer.

We have developed a plasma process to form an interface layer, fused with the underlying surface, and containing covalent attachment sites.

The mildly hydrophilic property of the interface layer stabilizes the biomolecule’s native conformation, resulting in excellent retention of bioactivity.

The plasma process uses small quantities of environmentally friendly and biocompatible vaporized precursors to form the fused interface layer.

Energetic ion bombardment is the key to achieving the covalent coupling and to minimizing hydrophobic recovery so that functionality of the bound biological molecules is maintained.

Protein immobilization is as simple as for physical adsorption but achieves a strong covalent attachment equivalent to immobilisation through complex chemical linker strategies.

Applications

Polymerisation of acrylates, alkenes, dienes and alkynes; Low cost polymerisation catalysts.

Principal inventors

  • Professor Marcela Bilek
  • Professor David McKenzie

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