Semiconductor nanowire field-effect transistors (FETs) have attracted great
interest as biosensors for point-of-care testing (POCT) because they allow label-free,
real-time, ultrasensitive detection using devices that are compact, low power, and
easily integrable with on-chip electronic systems. In the past twenty years, these
devices have seen significant breakthroughs in various aspects of device development,
such as design, fabrication, and surface functionalization, as well as in diagnostic
applications, having demonstrated femtomolar detection of DNA, RNA, proteins, and
small molecules. In this chapter, we highlight notable advancements in nanowire-based
FET biosensors in the past decade, focusing, in particular, on biomarker detection using
silicon, indium oxide and zinc oxide nanowire FET devices. Recent developments
include new CMOS-compatible fabrication techniques, unconventional device
configurations and detection schemes, coatings to enhance sensing stability, novel
bioreceptor elements and surface modification schemes for sensitivity enhancement, as
well as sample processing and portable readout systems. Furthermore, we also include
studies that have used nanowire FETs in concert with pattern recognition methods for
disease diagnosis using exhaled breath. The growing body of research indicates that
practical solutions to long-standing issues are at hand, bringing nanowire-FET
biosensors ever closer to adoption in real-world POCT applications.
Keywords: Biosensor, Biomarker, Diagnosis, Field effect, Indium oxide,
Nanowire, Nanomaterial, Point of care, Sensor, Silicon, Semiconductor,
Transistor, Zinc oxide.
