Overcome Debye Length Limitations for Biomolecule Sensing Based on Field Effective Transistors

Biosensors based on field effective transistor (FET) have aroused tremendous attention in the past few years owning to their huge application in drug discovery, disease diagnosis and environmental monitoring. The FET biosensors possess small volume, high sensitivity at ultra-low concentration, considerable mechanical strength, as well as excellent stability in solution, which plays a vital role in the point of care testing (POCT) systems. Recent advances have summarized some progress involved in the improvement of morphology and structure of channel materials, the functionalization of organic molecule, the influence of device operation and sensing environment on the detecting performance. However, for FET biosensors, the charge screening phenomena were inevitable in the solution, which seriously degrade the device performance. In this article, we summarize recent advances to overcome debye length limitations for biomolecule sensing based on FET. We will firstly describe the charge screening mechanism, then focous on the strategy to overcome charge screening, including synthesizing special channel materials with crumpled morphology, designing aptamer binding mode, and modulating device measurement. Finally, we discuss the major challenges and perspectives about overcoming debye length limitations of FET biosensors. These summaries provide further insights to realize real-time, lable-free, high-sensitivity FET sensors for medical healthcare.