Molecular surfactants,
which are based on a water-insoluble tail
and a water-soluble head, are widely employed in many areas, such
as surface coatings or for drug delivery, thanks to their capability
to form micelles in solution or supramolecular structures at the solid/liquid
interface. Electrolyte-gated organic field-effect transistors (EGOFETs)
are highly sensitive to changes occurring at their electrolyte/gate
electrode and electrolyte/organic semiconductor interfaces, and hence,
they have been much explored in biosensing due to their inherent amplification
properties. Here, we demonstrate that the EGOFETs and surfactants
can provide mutual benefits to each other. EGOFETs can be a simple
and complementary tool to study the aggregation behavior of cationic
and anionic surfactants at low concentrations on a polarized metal
surface. In this way, we have monitored the monolayer formation of
cationic and anionic surfactants at the water/electrode interface
with p
-
type and n
-
type devices,
respectively. On the other hand, the operational stability of EGOFETs
has been dramatically enhanced, thanks to the formation of a protective
layer on top of the organic semiconductor by exposing it to a high
concentration of a surfactant solution (above the critical micelle
concentration). Stable performances were achieved for more than 10
and 2 h of continuous operation for p
-
type and n-type
devices, respectively. Accordingly, this work points not only that
EGOFETs can be applied to a wider range of applications beyond biosensing
but also that these devices can effectively improve their long-term
stability by simply treating them with a suitable surfactant.