Abstract
The NH4 +‐ion‐sensitive field effect transistor (ISFET) in a batch system and the polymer‐based microchip with NH4 +‐ISFET showed almost the similar performance in low detection limits, dynamic range of the calibration curve, the slope sensitivity, and the stability of the potential. From the results, the polymer‐based microchip with ISFET fabricated using polystyrene plates and stainless wires as a template of channel can be useful for several applications in a microchip technology.