A prototype electrochemical chromatographic column for use with proteins

We developed electrochemical hardware and media targeted for protein chroma tography. Two types of stationary phases were investigated. The first compr ised gold-plated stainless 316L beads coated with a self-assembled monolaye r of 6-mercaptohexan-1-ol and was expected to behave like an ion-exchange r esin in the presence of an electric field. The second stationary phase comp rised the first stationary phase with further functionalization with immobi lized heme moieties and was expected to behave like an immobilized metal af finity resin. We tested the apparatus with both stationary phases using rib onuclease A as a model protein and applied potentials from -0.3 to +0.3 V v ersus the saturated calomel electrode. Despite low binding capacities, we d emonstrated that protein retention on both stationary phases could be contr olled with an applied potential. The greatest extent of electromodulation w as achieved with the mercaptohexanol-based ion-exchange media.