New insight into a microfluidic-based bipolar system for an electrochemiluminescence sensing platform.

In this work, a novel style of a microfluidic-based bipolar system with two-direction driving electrodes and dual-channel configuration was described for the first time, which could reach 100% current efficiency in theory. More importantly, the background signal from the integrated driving electrodes was completely eliminated, when this unique design was used to construct an electrochemiluminescence (ECL) sensing platform. First, universal pH indicator was employed to study the mechanism and demonstrate that this new bipolar system possessed 100% current efficiency theoretically. Then, the Ru(bpy)₃²⁺/TPrA ECL system was introduced to construct the dual-channel bipolar ECL sensing platform, and the results of visual ECL experiments proved that the background signals from the driving electrodes were completely dispelled with our design. To illustrate the promising applications of this dual-channel device, TPrA, dopamine (DA), H₂O₂, and K₃Fe(CN)₆ were detected as model targets under different principles.