Single electron transfer events in both immobilized and freely diffusing redox-active molecules can now be studied with some facility using a special kind of bimodal nanoelectrochemical-nanophotonic architecture – the electrochemical zero-mode waveguide (E-ZMW). The E-ZMW consists of a high density array of recessed dual-ring electrode nanopores that can moderate the interaction between single electron-transfer events and fluorescence emission, in the zeptoliter optical confinement volume of a zero-mode waveguide. The dual optical-electrochemical functionality makes it possible to perform single molecule spectroelectrochemical measurements under redox cycling conditions – both when the upper electrode is potential-controlled and using self-induced redox cycling. These have been performed with flavin mononucleotide, FMN, whose isoalloxazine chromophore is fluorescent in the oxidized state and dark in the reduced state, FMNH₂. This property permits the redox state of single FMN molecules to be followed by fluorescence, with each high/low luminescence transition signaling single molecule cycling. Capture efficiencies are characterized as a function of the potential applied to the upper ring electrode, and single molecule electrochemical-spectroscopic cross-correlation measurements are performed as a function of nanopore occupancy down to <n> ~0.001.