Fig. 3
(a) Schematic representation of dual in-plane nanopore sensor. The nanopore and nanochannel walls were negatively charged, leading to the development of an electrical double layer (EDL) on the wall surfaces, which induced an electroosmostic flow (EOF). Negatively charged proteins such as IgG, streptavidin, and myoglobin traveled against the EOF, while positively charged cytochrome C traveled with the EOF. lpore = length of the pore (~ 10 nm), Wpore = width of the pore (~ 10 nm), μep = electrophoretic mobility, μeo = electroosmotic flow. (b) Length, voltage drop, and electric field strength within the nanopore and nanochannel flight tube. Voltage drops were calculated using a COMSOL simulation applied for the entire sensor fluidic network. (c) Apparent mobilities of the four model proteins through the nanopore and nanochannel flight tube. Negative values represent apparent mobilities of proteins that travel against the EOF, while positive values represent the apparent mobilities of proteins that travel in the same direction as the EOF. Equation (5) was used to calculate the apparent mobilities. Apparent mobilities were calculated assuming there is no chromatographic effect on the movement of protein molecules through both the nanopore and the nanochannel.
