Abstract
In the past few years biosensing concepts based on organic field-effect
transistors (OFETs) have attracted more and more attention. Here organic
electronics benefit especially from the fact that solution-processable
organic thin films can be used in flexible and disposable sensors.
Additionally, the outstanding biocompatibility of many organic materials
allows the use of organic sensing devices for in-vivo
applications and permits the design of biodegradable sensors.
Starting from the basic principles of organic thin-film transistors, this
chapter will present the state of the art of biosensing approaches based on
OFETs, either back-gated or electrolyte-gated, focusing in particular on
different functionalization methods to achieve a selective response of the
OFET towards biologically relevant molecules. We present recently published
applications of organic thin-film transistors ranging from the detection of
biomolecules such as DNA, proteins, and enzymes to the sensing and
stimulation of electrical activity potentials of neurons. The sensing
mechanism and the influence of the Debye screening length on the detection
of biomolecules will be discussed.
Background and introduction
Early and correct diagnosis of diseases plays a crucial role in modern
medicine. For several decades researchers have been working on the discovery
of biomarkers, molecular indicators giving early information about various
diseases. For detection of the increasing number of biomarkers, low-cost,
fast, and reliable methods are required.