A Nanoscale Multichannel Closed Bipolar Electrode Array for Electrochemiluminescence Sensing Platform

In this work, we report a nanoscale multichannel closed bipolar electrode (BPE) array based on the poly­(ethylene terephthalate) (PET) membrane for the first time. With our design, oxidants, coreactants, quenchers, and even biomarkers can be detected in a Ru­(bpy)<sub>3</sub><sup>2+</sup>/TPA (tripropylamine) electrochemiluminescence (ECL) system. The multichannel PET membrane was etched according to our desire by NaOH, and then Au nanofibers were decorated in the inner region of the channel as a BPE array. Using ECL as a signal readout, a series of targets including TPA, Ru­(bpy)<sub>3</sub><sup>2+</sup>, dopamine, H<sub>2</sub>O<sub>2</sub>, alpha-fetoprotein (AFP), and carcino-embryonic antigen (CEA) can be detected with this device. The practical application of the proposed multichannel closed BPE array was verified in the detection of AFP and CEA in human serum with satisfying results. This kind of nanoscale device holds promising potential for multianalysis. More importantly, as the PET membrane used in this device can be etched with a desirable diameter (nano- to microscale) and different BPE array densities (ion tracks of 10<sup>8</sup>/cm<sup>2</sup>, 10<sup>6</sup>/cm<sup>2</sup>, 10<sup>4</sup>/cm<sup>2</sup>), our design can be served as a useful platform for future advances in nanoscale bipolar electrochemistry.