In a nutshell
Nitrocatechols are able to covalently link to metal and metal oxide surfaces. Because of the stabilizing nitro-group, the compounds are resistant to oxidation at higher pH values than is the case with their parent catechol derivatives.
Spontaneously assembling monomolecular coating.
Iron oxide (Fe3O4), titanium oxide (TiO2), aluminum oxide (Al2O3), tantalum and niobium pentoxides (Ta2O5, Nb2O5), indium tin oxide (ITO), gold (Au) and, in general, oxides from transition metals
- Covalent immobilization, self-limiting to the formation of a monolayer
Nitrodopamine and nitrodopa can be used for amination, introduction of surface charge and electrostatic stabilization of particles. In addition steric stabilization and protection from biofouling, can be obtained using the PEGylated or dextran functionalized compounds.
Specific binding can be obtained using biotin-neutravidin coupling schemes.
Perfluorophenyl azide (PFPA)-functionalized nitrodopamine can be used as an adhesion promoter for nonspecific UV-activated binding of most molecules that are in proximity to the functionalized surface.
Perfluorinated alkyl chains to obtain hydro- and oleo-phobic surfaces
- Functionalization of magnetic nanoparticles for magnetic-resonance applications.
- Amine-functionalized metal oxide surfaces for sensing-device chips for diagnostics and bio-analytics
- Reactive coatings for coupling applications in proteomics and genomics
- Selective adsorption on oxide-patterned bio-chips 
- Anti-bacterial, cell-resistant treatment of metallic medical devices
- Improved tissue integration with bioactive coatings, using peptides or growth factors
- Surfaces with selective biological response to different cell types
- Adhesion promoters and primers
Other technical applications
- Non-fouling, anti-bacterial coatings
- Easy-to-clean surfaces
How it works!
Biomimetic nitro-catechols derived from Anachelin H
Coating of iron oxide particles for MRI: Surface-functionalization of nano-particles using nitrocatechols
The siderophore Anachelin H, isolated from cyano-bacteria, was found to have an extreme binding capability for dissolved iron(III) ions due to the presence of a double-ring structure consisting of a catechol and a quaternary amine, known as anacat .
Nitrodopamine and nitrodopa are synthetic mimics of anacat and have proven to be powerful surface-active compounds that are useful for bioresistant surface functionalization  and hydrophobization of various substrates . In addition they are very strong binding dispersants for magnetite [4a-e] and other nanoparticles .
In addition to the lower pKa of the hydroxy groups compared to pyrocatechol, the main advantage of this new class of surface-active molecules is their high stability against oxidation, even at basic pH, proving them superior to non-modified catechol derivatives in a range of applications, especially the stabilization of nanoparticles.
In comparison to electrostatic binding, nitrocatechols form covalent coordinative bonds with a range of metallic and metal-oxide surfaces, such as TiO2, Fe-based materials (steel, magnetite particles), alumina and gold.