April 16, 2013

The Use of UV-Cross-Linkable Di-Block Copolymers as Functional Reaction Surfaces for Microelectrode Arrays

Libo Hu, Matthew D. Graaf, and Kevin D. Moeller

Journal of The Electrochemical Society, 160 (7) G3020-G3029 (2013)

Three types of UV-cross-linkable di-block copolymers have been developed as coating for microelectrode arrays. All three polymers share the same PCEMA block for cross-linking reaction. The PBrSt-b-CEMA polymer was shown compatible with a series of Pd(0)- and Cu(I)-catalyzed reactions. It was compatible with electrochemical signaling experiments, although it showed non-specific binding to proteins at higher concentrations. In order to study weak binding interactions, PCEMA-b-PPEGMA was developed to reduce non-specific binding. However, it was shown not to be a stable enough surface for array-based reactions. In an effort to make a tunable surface, PCEMA-b-BSt was made and was shown to be compatible with Suzuki reactions on the array, however, the inability of achieving a stable current deemed it incompatible with signaling experiments. The use of a pinacol protected PCEMA-b-pBSt polymer solved these issues. The protected polymer could be site-selectively deprotected, transesterified, and functionalized with Cu(II)-catalyzed reactions. It is also compatible with the electrochemical impedance experiments used to signal binding-events on the