Synthesis and characterisation of a mussel-inspired hydrogel film coating for biosensors

Mussel-inspired, catechol-containing monomers are being increasingly utilised to design versatile, adhesive, functional copolymers. This work reports the synthesis and detailed characterisation of a novel terpolymer comprising dopamine methacrylamide (DMA), in order to produce surface coatings capable of acting as biosensors for, e.g., toxins. DMA is copolymerised with 2-hydroxyethyl methacrylate (HEMA) and glycidyl methacrylate (GMA) using free radical polymerisation. The copolymers are subsequently deposited as a thin film using spin-coating. It is demonstrated that a terpolymer comprising HEMA, GMA and DMA can immobilise an IgG antibody on the film surface. The terpolymer therefore has the potential to be used as a coating in biosensing devices. It is also demonstrated that the presence of DMA impacts the copolymer properties. In-situ ellipsometry is used to confirm the important role of the catechol group on copolymer adhesion and significant desorption was observed in the absence of DMA.