Signal enhancement mechanism for dual-gate ion sensitive field effect transistor in on-chip disease diagnostic platform

A dual-gate ion-sensitive field effect transistor (ISFET) comprising:

• a device substrate having a first surface and a second surface, the first surface opposite the second surface;
• a gate structure disposed over the first surface, the gate structure including:
• a gate dielectric layer, and
• a gate electrode layer disposed between a source region and a drain region in the device substrate, wherein a channel region is defined in the device substrate between the source region and the drain region;
• and
• a fluidic gate structure disposed over the second surface, wherein the fluidic gate structure includes a sensing well disposed over the channel region, the sensing well including:
• a sensing layer configured to react with a first ion generated from an enzymatic reaction that occurs when an enzyme-modified detection mechanism detects a target analyte and a second ion generated from a reaction between a product of the enzymatic reaction and an iron-containing constituent, such that the dual-gate ISFET generates an electrical signal.

A method for analyzing using a dual-gate ion-sensitive field effect transistor (ISFET) wherein the dual-gate ISFET includes a fluidic gate structure and a gate structure, wherein the fluidic gate structure and the gate structure are disposed over the opposite surfaces of a device substrate, the method comprising:

• generating electrical characteristic data based on an an electrical signal generated from a sensing layer of the fluidic gate structure reacting with:
• a first ion generated from an enzymatic reaction when an enzyme-modified detection mechanism detects a target analyte, and
• second ion generated when a product of the enzymatic reaction reacts with a constitutent of an electrolyte solution;
• and determining a presence or a quantity of target analytes based on the electrical characteristic data.