Closed bipolar electrode (CBE) geometries can be used to couple analytically-directed redox processes occurring in one microfluidic cell - the analytical cell - to a variety of optical readouts (fluorescence, absorption, surface plasmon resonance shifts) occurring in a remote microfluidic cell – the reporter cell. In the fluorescence version, oxidation or reduction of reversible analytes in the analytical cell is accompanied by reduction or oxidation, respectively, on the proximal portion of a CBE and then monitored by the accompanying oxidation of dihydroresorufin or reduction of resorufin in the reporter cell. Changes in fluorescence intensity have been used to determine Ru(NH₃)₆³⁺ at sub-nM concentrations, demonstrating high sensitivity fluorescence-mediated electrofluorigenic sensing. An electrochromic version of the strategy was developed using a methylviologen (MV) reporter system. CBE-enabled devices based on two thin-layer-cells of ITO and Pt were fabricated to couple an analytical reaction with a MV reporter reaction, producing a color change in the reporter cell, that was readout by a smartphone. Evolution of the device replaced the potentiostat with batteries to control potential, and augment the smartphone, thereby demonstrating the simplicity and portability of the device. This strategy was recently extended to non-electroactive analytes, by coupling enzyme-catalyzed oxidoreductases in the analytical cell to the same MV electrochromic reporter system, a construct which is being employed to develop a multiplex assay for sepsis biomarkers.