Sensing device and related methods

The present invention is generally directed to devices and methods for sensing a variety of biologically-related substances. In a device aspect, the present invention is directed to a multilayer device for sensing metal ions, biological molecules, or whole cells. The device comprises: a) one or more cavities that provide for the introduction of a sample to be analyzed and one or more channels that provide for exit of the sample, or one or more channels that provide for the introduction and exit of the sample; b) one or more single-walled carbon nanotubes presented to the one or more cavities or one or more channels; c) a plurality of electrodes electrically connected to the one or more single-walled carbon nanotubes; and, a reference gate electrode presented to the one or more cavities or one or more channels. In a method aspect, the present invention is directed to a method for sensing species such as a metal, biological cells, and one or more biological molecules using the device.