Preventing Nonspecific Adsorption on Polymer Brush Covered Gold Electrodes Using a Modified ATRP Initiator

Biological systems have a tendency to adsorb nonspecifically onto a solid substrate, thus reducing the efficacy of the interface being used in biorecognition. This nonspecific adsorption is a common problem in the development of biosensors as it typically reduces the efficacy of the sensor platform. In this manuscript we report the synthesis of an oligo(ethylene glycol) (OEG) containing ATRP (atom transfer radical polymerization) thiol initiator and demonstrate the role of this initiator in preventing nonspecific adsorption of IgG antibodies on chemically functionalized gold electrode surfaces using cyclic voltammetry. A new synthetic route for the synthesis of the new ATRP thiol initiator in high yields has been reported. Surface initiated poly(acrylic acid) brushes grown off the gold surface with modified OEG containing and conventional ATRP thiol initiators were chemically modified with 2,4-dinitrophenyl (DNP) groups. Amperometric studies were carried out on gold electrodes modified with DNP-PAA brushe...