Patent ID: 7943970
Filing Date: 2011-05-17
Classification: G01N

Abstract:
1. A method of detecting target bio-molecules using the same field effect transistor, the method comprising: contacting a first sample having known target bio-molecules with a sensing surface of a field effect transistor; measuring a first electric signal of the field effect transistor; contacting a second sample with the sensing surface of the same field effect transistor; measuring a second electric signal of the field effect transistor; and comparing the first electric signal with the second electric signal, wherein bio-molecules are not fixed on the sensing surface and wherein the field effect transistor comprises: a substrate composed of a semiconductor material; a source region and a drain region which are formed to be separate on the substrate and doped to have a polarity opposite to a polarity of the substrate; a channel region disposed between the source region and the drain region; an insulating layer which is disposed on the channel region and has the sensing surface; and a reference electrode opposedly disposed to the sensing surface; wherein the reference electrode is separated from the insulating layer, and wherein the comparing of the first electric signal with the second electric signal comprises calculating a compared signal according to Formula (I) below