This disclosure provides, among other things, a nanofluidic device sensing device is provided. In certain embodiments, the device contains: a) a channel comprising a floor and a ceiling, b) an array of charge sensors in the floor and/or ceiling of the channel, arranged along the longitudinal axis of the channel; c) a capture area in the floor and/or ceiling of the channel at the entrance end of the channel; and d) a first electrode and a second electrode, wherein the first and second electrodes are positioned to provide an electrophoretic force along the longitudinal axis of the channel. Other embodiments, e.g., methods, are also described.