Fig. 1
From: Role of outer surface probes for regulating ion gating of nanochannels
Design principle and experimental setup. a Graphical illustration of nanochannels functional regions (NOS, NIW, and NIW + NOS) associated with ion-gating efficiency to be investigated. b Cartoon presentation of DNA-based functional elements (FE) regionally assembled at different regions of metal-decorated AAO nanochannels. Shown inset is a DNA traditional sandwich (TS) tethered with double-MB electrochemical tags. CP capture probe, SP signal probe. c Schematic diagram of the nanochannels’ dual-current setup. Ion transport (IT) and electron transfer (ET) through inner-wall and outer-surface DNA-functionalized nanochannels (NIWFE + NOSFE) are schematically presented, which simultaneously generate DNA framework mediating ionic current (IC, left panel) and electrolytic current (EC, right panel) signals through a two-electrode picoammeter and a three-electrode electrochemical analyzer, respectively. WE, working electrode; AE, auxiliary electrode; RE, reference electrode. Of note, the metal-decorated AAO nanochannels’ membrane serves as WE and is in electric touch with a conducting strip on a polymethyl methacrylate (PMMA) plate that is directly connected to the electrochemical analyzer
