Highly sensitive and rapid detection of carbon nanotube-based biosensors using immune binding reaction

Abstract

The field effect transistor (FET) based on a network of single-walled carbon nanotubes (SWCNTs) that can perform sensitive and selective real-time monitoring of target analytes are tremendously valuable for various sensing applications. Here carbon nanotube-field effect transistors (CNT-FETs) were functionalized with antibody-binding fragments as a receptor, and the binding event of specific target antigen onto the fragments was detected by monitoring the gating effect caused by the charges of the target antigen. We were able to lower the detection limit to a protein concn. of 100 ng/mL, without cutting antibody or labeling the target proteins. Our results show that there is good correlation between the two platforms with respect to detecting analytes.