Fabrication and characteristics of biofet albumin sensor using new self-assembled monolayer

The BioFET albumin sensor with the gold gate as a gate material was fabricated and its characteristics were investigated. To enable label-free molecular detection, the BioFET gate surface was chemically modified by new immobilized molecular receptors, so called self-assembled monolayer (SAM) synthesized by a thiazole benzo crown ether ethylamine (TBECA)-thioctic acid to bind albumin-antibody. In this paper an albumin antigen-antibody binding generated above the gate surface was used as an albumin sensing mechanism of the BioFET. So the drain current was varied by antigen-antibody interactions on gate surface because the albumins have a negative charge. Experimental results related to the formation of SAM, antibody, and antigen were obtained from quartz crystal microbalance and surface plasmon resonance.