A Darlington pair sensor comprising: an amplifying bipolar junction transistor horizontally disposed on a substrate, the amplifying BJT having a horizontal emitter, a horizontal base, a horizontal collector, and a common extrinsic base/collector, the common extrinsic base/collector being an amplifying BJT extrinsic base for the amplifying BJT and the common extrinsic base/collector being in contact with and disposed upon the horizontal base; a sensing BJT in a vertical orientation with respect to the amplifying BJT, the sensing BJT having a vertical emitter, a vertical base, an extrinsic vertical base separated into a left extrinsic vertical base and a right extrinsic vertical base (2450L, 2450R), and the common extrinsic base/collector, the common extrinsic base/collector also being a sensing BJT collector for the sensing BJT; wherein the left extrinsic vertical base is in contact with a left side of the vertical base and the right extrinsic vertical base in in contact with a right side of the vertical base and the left extrinsic vertical base and right extrinsic vertical base are separated from one another; a sensing trench being a spatial void capable of receiving fluids containing one or more sensed substances, the sensing trench being adjacent to one of the left extrinsic vertical base and the right extrinsic vertical base which is a sensing extrinsic vertical base, the one of the left extrinsic vertical base and the right extrinsic vertical base that is not the sensing extrinsic vertical base being a control extrinsic vertical base; and a sliver sensing surface, the sliver sensing surface being a conductive material between the sensing trench and the sensing extrinsic vertical base and the sliver sensing surface being in electrical contact with the sensing extrinsic vertical base. an amplifying bipolar junction transistor horizontally disposed on a substrate, the amplifying BJT having a horizontal emitter, a horizontal base, a horizontal collector, and a common extrinsic base/collector, the common extrinsic base/collector being an amplifying BJT extrinsic base for the amplifying BJT and the common extrinsic base/collector being in contact with and disposed upon the horizontal base; a sensing BJT in a vertical orientation with respect to the amplifying BJT, the sensing BJT having a vertical emitter, a vertical base, an extrinsic vertical base separated into a left extrinsic vertical base and a right extrinsic vertical base (2450L, 2450R), and the common extrinsic base/collector, the common extrinsic base/collector also being a sensing BJT collector for the sensing BJT; wherein the left extrinsic vertical base is in contact with a left side of the vertical base and the right extrinsic vertical base in in contact with a right side of the vertical base and the left extrinsic vertical base and right extrinsic vertical base are separated from one another; a sensing trench being a spatial void capable of receiving fluids containing one or more sensed substances, the sensing trench being adjacent to one of the left extrinsic vertical base and the right extrinsic vertical base which is a sensing extrinsic vertical base, the one of the left extrinsic vertical base and the right extrinsic vertical base that is not the sensing extrinsic vertical base being a control extrinsic vertical base; and a sliver sensing surface, the sliver sensing surface being a conductive material between the sensing trench and the sensing extrinsic vertical base and the sliver sensing surface being in electrical contact with the sensing extrinsic vertical base.