Stably electro-switchable poly-allyloxy hydroxypropyl sulfonate branched brush towards reversible capture and release of proteins and cells

An anion-terminated branched brush was designed, and confirmed to have reversibly electrical field responsive characters, which enables the stable and reversible manipulation of the adhesion behaviors of proteins and cells in a controllable manner. To proof the concept, poly sodium allyloxy hydroxypropyl sulfonate (poly-AHPS) branched brush was grafted from electrically conductive indium tin oxide (ITO) glass slide, and was demonstrated having two states: the stretched polymer brush under negatively charged and the rolled contractive polymer structure under positively charged. The electrical capture and release of anti-Ig G via the above poly-AHPS polymer branched brushes were successfully implemented, which indicated a potential in the disease diagnosis. The electrical capture and release of K562 cells were also accomplished through the poly-AHPS polymer branched brushes, which announced a possibility in the diagnosis of myelogenous leukemia. We anticipate the electro-switchable polymer branched brushes would be adopted in the electrical manipulation of adhesion behaviors of proteins and cells, and facilitate the applications in construction of micro-sensors and micro-actuators.