A plastic electronic circuit based on low voltage, organic thin-film transistors for monitoring the X-Ray checking history of luggage in airports
Stefano Lai, Giulia Casula, Piero Cosseddu, Laura Basiricò, Andrea Ciavatti, Franck D’Annunzio, Christophe Loussert, Vincent Fischer, Beatrice Fraboni, Massimo Barbaro, Annalisa Bonfiglio
Organic Electronics 58, 263-269 (2018)
A circuit based on low voltage Organic Field-Effect Transistors (OFETs) and conceived for monitoring the security check history of luggage in airport environment is reported. An OFET-based, direct X-Rays detector is used as sensing element and integrated in an organic circuit for digitization and memorization of the X-Ray exposure event. An integrated interface to a commercial RFID chip and antenna is also realized to allow remote readout of the circuit status. The operation mechanism of the circuit is described and a complete explanation of the strategy adopted for circuit design is reported. Simulations of the systems in Cadence® Virtuoso environment are presented: X-Ray response of the sensor is modelled, and the overall functionality of the detection and memorization schema are demonstrated. Fabrication and characterization of the circuit under X-Rays in laboratory environment are described. In particular, the correct functionality of the circuit is demonstrated, as well as its actual capability in driving the commercial RFID tag system. The robustness of the circuit to aging and exposure to X-Rays in operation conditions is finally discussed.
Electronic Detection of DNA Hybridization by Coupling Organic Field-Effect Transistor-Based Sensors and Hairpin-Shaped Probes
Corrado Napoli, Stefano Lai, Ambra Giannetti, Sara Tombelli, Francesco Baldini, Massimo Barbaro, Annalisa Bonfiglio
Sensors 18 (4), 990 (2018)
In this paper, the electronic transduction of DNA hybridization is presented by coupling organic charge-modulated field-effect transistors (OCMFETs) and hairpin-shaped probes. These probes have shown interesting properties in terms of sensitivity and selectivity in other kinds of assays, in the form of molecular beacons (MBs). Their integration with organic-transistor based sensors, never explored before, paves the way to a new class of low-cost, easy-to-use, and portable genetic sensors with enhanced performances. Thanks to the peculiar characteristics of the employed sensor, measurements can be performed at relatively high ionic strengths, thus optimizing the probes’ functionality without affecting the detection ability of the device. A complete electrical characterization of the sensor is reported, including calibration with different target concentrations in the measurement environment and selectivity evaluation. In particular, DNA hybridization detection for target concentration as low as 100 pM is demonstrated.
Floating Gate, Organic Field-Effect Transistor-Based Sensors towards Biomedical Applications Fabricated with Large-Area Processes over Flexible Substrates
Stefano Lai, Fabrizio Antonio Viola, Piero Cosseddu, Annalisa Bonfiglio
Sensors 18 (3), 688 (2018)
Organic Field-Effect Transistors (OFETs) are attracting a rising interest for the development of novel kinds of sensing platforms. In this paper, we report about a peculiar sensor device structure, namely Organic Charge-Modulated Field-Effect Transistor (OCMFET), capable of operating at low voltages and entirely fabricated with large-area techniques, ie, inkjet printing and chemical vapor deposition, that can be easily upscaled to an industrial size. Device fabrication is described, and statistical characterization of the basic electronic parameters is reported. As an effective benchmark for the application of large-area fabricated OCMFET to the biomedical field, its combination with pyroelectric materials and compressible capacitors is discussed, in order to employ the proposed device as a temperature pressure sensor. The obtained sensors are capable to operate in conditions which are relevant in the biomedical field (temperature in the range of 18.5–50 C, pressure in the range of 10 2–10 3 Pa) with reproducible and valuable performances, opening the way for the fabrication of low-cost, flexible sensing platforms.