In this review, we will provide an overview of the current understanding of AD biomarkers, describe the working principle of FET biosensors, and highlight recent advances in the development of CNT-based FET biosensors for the detection of AD biomarkers, with a particular emphasis on Aβ and tau proteins. We will also discuss the potential of these biosensors for clinical diagnosis and the challenges that need to be addressed for their successful translation into practical applications.