A simple approach has been developed to functionalize various substrates, such as gold and polyvinylchloride, with dopamine methacrylamide—a molecule with adhesive properties that mimic those of mussels—to produce a versatile and general platform for subsequent surface modification. With active double bonds on the surface, various polymers, such as poly([2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl) ammonium hydroxide (PMEDSAH) and poly(N-vinylpyrrolidone) (PVP), can be grafted by conventional radical polymerization. Double bond surface functionalization and subsequent polymer grafting have been verified by static water contact angle, Fourier transform infrared-attenuated total reflectance (FTIR-ATR) spectroscopy and X-ray photoelectron spectroscopy (XPS) measurements. Protein adsorption assays showed that the polymer-modified substrates have good protein-resistant properties. Considering the advantages of facility, versatility and substrate-independence, this method should be useful in designing functional interfaces for bioengineering applications.