Finally, we support these findings with the results of numerical simulations, which show that a 3D-electrode i) generates an IDZ that extends the full depth of the channel, while a planar electrode does not, ii) better retains charged species upstream of this junction, and iii) constrains the size of fluid vortices overlying the Au microband electrode. A key point is that, based on the mechanism gains are expected to be generalizable to charged biomarkers (indeed, we are currently pursuing such applications). This platform lays a foundation for further advancements because it utilizes off-the-shelf microbeads, which make its construction straightforward and lend versatility to its composition and function. These advancements are significant because they address the most pressing challenges to the application of ICP-based preconcentrators to bioanalysis. and 300 nM dye-linked albumin (Texas Red BSA)). First, we evaluated the current voltage curves (CVCs) obtained when a series of voltages was applied. The details of this experiment are included in the Supporting Information (SI). Figure is a plot of the CVCs obtained for these three solutions. Ohmic, limiting, and overlimiting regions, corresponding to three distinct slopes were observed only in the Tris buffer solution. This result supports the proposed mechanism because the electrolyte ions of the other two BGE solutions, K + , Na + , NO3 -and HPO4 2-/H2PO4 -, do not react with OH -generated at the planar electrode to form an uncharged product as does TrisH + . For example, upon reaction with OH -, H2PO4 -becomes the more highly charged species HPO4 2-.