A field effect transistor biosensor with a γ-pyrone derivative engineered lipid-sensing layer for ultrasensitive Fe3+ ion detection with low pH interference

Field effect transistors have risen as one of the most promising techniques in the development of biomedical diagnosis and monitoring. In such devices, the sensitivity and specificity of the sensor rely on the properties of the active sensing layer (gate dielectric and probe layer). We propose here a new type of transistor developed for the detection of Fe3+ ions in which this sensing layer is made of a monolayer of lipids, engineered in such a way that it is not sensitive to pH in the acidic range, therefore making the device perfectly suitable for biomedical diagnosis. Probes are γ-pyrone derivatives that have been grafted to the lipid headgroups. Affinity constants derived for the chelator/Fe3+ complexation as well as for other ions demonstrate very high sensitivity and specificity towards ferric ions with values as high as 5.1010M and a detected concentration as low as 50fM. •Biofet based on the use of a lipid monolayer as gate dielectric.•γ-Pyrone derivative modified lipid monolayer shows no pH sensitivity in the acidic range.•γ-Pyrone derivative modified lipid monolayer exhibits high specificity towards ferric ions.•Very high chelator/ferric ions affinity constant for 2D systems.•Detection of ferric ions in the femtomolar range.