Significance of the Science

Biosensors are essential for detecting disease-related biomarkers, but conventional designs often face a tradeoff between sensitivity and commercial practicality. Field-effect transistors (FETs) have shown strong potential due to their electrical readout and scalability, yet challenges remain in boosting their signal response while keeping devices simple and cost-effective. This study introduces a new transistor architecture—using a remote floating gate and a reduced graphene oxide (rGO) sensing layer—that significantly enhances biosensing performance without requiring complex or bulky instrumentation. 

Highlights

• Novel transistor architecture: remote floating-gate field-effect transistor (RFGFET) with rGO sensing layer

• Amplified sensitivity: output signal improved by more than 30x compared with conventional FET biosensors

• Achieves femtomolar-scale sensitivity for target molecules

• Scalable and versatile design: compatible with various surface modifications for detecting different biomarkers

• Avoids bulky optical setups and enables potential integration into portable biosensing platforms

Summary

The study reports the development of a remote floating-gate field-effect transistor (RFGFET) for biosensing applications. By integrating a reduced graphene oxide (rGO) layer as the sensing surface, the device demonstrated significantly improved transconductance and signal amplification compared with traditional FET biosensors. Experimental results showed over 30-fold enhancement in sensitivity, achieving detection limits down to the femtomolar range. The architecture separates the sensing gate from the transistor channel, reducing noise and allowing flexible chemical modification for diverse targets. This design provides a scalable pathway toward ultrasensitive, portable, and low-cost biosensors suitable for a wide range of diagnostic applications.

Read more: https://pubs.acs.org/doi/10.1021/acsami.2c04969