An organic ultralow voltage field effect transistor for DNA hybridization detection is presented. The transduction mechanism is based on a field-effect modulation due to the electrical charge of the oligonucleotides, so label-free detection can be performed. The device shows a sub-nanometer detection limit and unprecedented selectivity with respect to single nucleotide polymorphism.

An amperometric sensor based on an ITO electrode coated with ferrocene clicked PEDOT:PSS is described and the electrocatalytical performance of the device towards dopamine is assessed.

The ability of field effect transistors (FETs) to detect charge variations on the gate may be exploited for realizing chemo- and bio-sensors. In this paper, we focus our attention on a particular kind of field effect device, named organic charge modulated FETs, whose features can be optimized for charge detection in liquid solutions. The results of the measurement of different bio-related effects are shown. In particular, DNA hybridization and pH detection in liquid media are proposed. Finally, preliminary considerations about the applicability of these devices to the detection of the electrical activity of cells are also provided. The device has considerable potential for being employed as a reliable, high sensitivity, low cost technology for sensing signals derived from living systems

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All-Organic Electrochemical Transistors (OECTs) realized by employing Poly(3,4-EthyleneDiOxyThiophene) doped with Poly(Styrene Sulfonate) as conductive polymer show a dependence of their behavior on the gate to channel area ratio. This peculiarity has been investigated and the working mechanism has been explained in view of the behavior of the ionic component of the device. In particular, taking into account the current theory of OECT behavior, we have focused our attention on the role of the gate, trying to clarify if these devices may be considered as working in Faradaic or capacitive regime

Novel flexible PEDOT:PSS/PANI bilayered thin-film electrodes were successfully prepared by ink-jet printing of PEDOT:PSS on a PEN substrate and subsequent electrochemical polymerisation of PANI. Scanning electron microscopy (SEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to systematically investigate the structure, morphology and electrochemical behaviour of the electrodes. The PEDOT:PSS/PANI bilayer nanofilms have been tested as pH sensors. As a comparison, either PEDOT:PSS or PANI electrodes have been tested for pH measurements. The results show that the sensitivity of the PEDOT:PSS/PANI bilayer film is higher than that of PEDOT:PSS and PANI electrodes, indicating a synergistic effect of the two polymers. A reversible near-Nerstian behaviour of the open circuit voltage with pH was found, with a slope of 58.9 mV pH-1 unit in a wide range of pH values from 2 to 14

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