Self-assembled monolayers (SAMs) of organic molecules have been used for a wide range of applications in medicine, surface protection as well as (bio)electronic devices. Extensive efforts have been dedicated to implement biomolecules in gold based diagnostic tools. Using SAMs as an interface between metal surfaces and biological moieties. This modification allows for covalent attachment of receptors to gold, avoiding denaturation usually associated with physical adsorption approaches. In this context, thiol-SAMs containing ethylene glycol (PEG) subunits proved to be effective linkers to prevent nonspecific adsorption at the sensor surface. However, major drawbacks of thiol-SAMs such as limited thermal and long-term stability under ambient conditions as well as their sensitivity to oxidation of the sulfur headgroups hamper their application. Recently, stable traceless single-source N-heterocyclic carbenes (NHC) have been introduced as anchor groups on gold. Their thermal and chemical stability render these compounds interesting for biosensing applications. In the present work, the synthesis and characterization of water-soluble PEG substituted NHC-SAMs will be presented. These new NHC-SAMs materials will be applied to functionalize flat gold substrates. Furthermore, these functionalized gold substrates will be used to immobilize biological moieties and tested toward their applicability in biosensors.