Abstract: An electrical detector is provided that comprises a nanofluidic channel with an integrated nanoscale charge sensor. The charge sensor can be an unfunctionalized nanowire, nanotube, transistor or capacitor and can be of carbon, silicon, carbon/silicon or other semiconducting material. The nanofluidic channel depth is on the order of the Debye screening length. Methods are also provided for detecting charged molecules or biological or chemical species with the electrical detector. Charged molecules or species in solution are driven through the nanofluidic channel of the electrical detector and contact the charge sensor, thereby producing a detectable signal. Methods are also provided for detecting a local solution potential of interest. A solution flowing through the nanofluidic channel of the electrical detector contacts the charge sensor, thereby producing a detectable local solution potential signal.