The region ion sensitive field effect transistor, a novel bioelectronic nanosensor

Area of Science:

• Bioelectronics
• Nanosensors
• Field-Effect Transistors

Background:

• Conventional glucose sensors face limitations in sensitivity and sample volume.
• Development of novel biosensing platforms is crucial for early disease detection and monitoring.

Purpose of the Study:

• To construct and demonstrate a novel bioelectronic nanosensor based on region ion sensitive field effect transistor (RISFET) technology.
• To evaluate the sensor's performance in glucose detection, including linearity, limit of detection, and sensitivity.
• To explore the potential of RISFET technology for future nanobiosensing applications.

Main Methods:

• Fabrication of RISFET sensor chips using electron beam lithography.
• Measurement of glucose concentration by focusing negatively charged gluconate ions with an electric field.
• Utilizing a low-noise picoammeter for signal current response measurement.
• Investigating the effect of electrode dimensions and electric field strength on sensor performance.

Main Results:

• The RISFET nanosensor demonstrated good linearity for glucose detection in the ranges of 0-0.6 mM and 0-0.3 mM.
• Limits of detection were as low as 0.1 mM and 0.04 mM for the two sensor chip designs.
• Sensitivity reached 830 pA/mM with optimized electrode spacing (790 nm) and electric field strength.
• Increased electric field strength by five times enhanced sensitivity by 30 times, operating in sub-femtoliter volumes.

Conclusions:

• The developed RISFET nanosensor offers a highly sensitive and efficient method for glucose detection.
• The sensor's ability to operate in low sample volumes makes it promising for point-of-care diagnostics.
• Further modifications could enable single enzyme molecule trapping for advanced nanobiosensing applications.