Organic Electrochemical Transistors Integrated in Flexible Microfluidic Systems and Used for Label-Free DNA Sensing

Department of Applied Physics and Materials Research Centre, The Hong Kong Polytechnic University, Hong Kong, China.
Advanced Materials (Impact Factor: 15.41). 09/2011; 23(35):4035-40. DOI: 10.1002/adma.201102017
Source: PubMed

ABSTRACT Organic electrochemical transistors are integrated in flexible microfluidic systems. A novel label-free DNA sensor is developed based on devices with single-stranded DNA probes immobilized on gate electrodes. These devices successfully detect complementary DNA targets at low concentrations using a pulse-enhanced hybridization technique in microfluidic channels. Organic electrochemical transistors are excellent candidates for flexible, highly sensitive, and low-cost biosensors.

  • [Show abstract] [Hide abstract]
    ABSTRACT: The rising field of bioelectronics, which couples the realms of electronics and biology, holds huge potential for the development of novel biomedical devices for therapeutics and diagnostics. Organic electronic devices are particularly promising; the use of robust organic electronic materials provides an ideal biointerface due to their reported biocompatibility, and mechanical matching between the sensor element and the biological environment, are amongst the advantages unique to this class of materials. One promising device emerging from this field is the organic electrochemical transistor (OECT). Arguably, the most important feature of an OECT is that it provides local amplification and as such can be used as a high fidelity transducer of biological events. Additionally, the OECT combines properties and characteristics that can be tuned for a wide spectrum of biological applications. Here, we frame the development of the OECT with respect to its underlying optimization for a variety of different applications, including ion sensing, enzymatic sensing, and electrophysiology. These applications have allowed the development of OECTs to sense local ionic/biomolecular and single cell activity, as well characterization of tissue and even monitoring of function of whole organs. The body of work reviewed here demonstrates that the OECT is an extremely versatile device that emerges as an important player for therapeutics and diagnostics. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41735.
    Journal of Applied Polymer Science 01/2015; DOI:10.1002/app.41735 · 1.64 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We propose and demonstrate a sensitive diagnostic device based on an Organic Electrochemical Transistor (OECT) for direct in-vitro monitoring cell death. The system efficiently monitors cell death dynamics, being able to detect signals related to specific death mechanisms, namely necrosis or early/late apoptosis, demonstrating a reproducible correlation between the OECT electrical response and the trends of standard cell death assays. The innovative design of the Twell-OECT system has been modeled to better correlate electrical signals with cell death dynamics. To qualify the device, we used a human lung adenocarcinoma cell line (A549) that was cultivated on the micro-porous membrane of a Transwell (Twell) support, and exposed to the anticancer drug doxorubicin. Time-dependent and dose-dependent dynamics of A549 cells exposed to doxorubicin are evaluated by monitoring cell death upon exposure to a range of doses and times that fully covers the protocols used in cancer treatment. The demonstrated ability to directly monitor cell stress and death dynamics upon drug exposure using simple electronic devices and, possibly, achieving selectivity to different cell dynamics is of great interest for several application fields, including toxicology, pharmacology, and therapeutics. Copyright © 2015 Elsevier B.V. All rights reserved.
    Biosensors & Bioelectronics 02/2015; 68C. DOI:10.1016/j.bios.2015.01.073 · 6.45 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Organic printed electronics has attracted an ever-growing interest in the last decades because of its impressive breakthroughs concerning the chemical design of π-conjugated materials and their processing. This has an impact on novel applications, such as flexible and large-area displays, low- cost printable circuits, plastic solar cells and lab-on-a-chip devices. The organic field-effect transistor (OFET) relies on a thin film of organic semiconductor that bridges source and drain electrodes. Since its first discovery in the 80s, intensive research activities were deployed in order to control the chemico- physical properties of these electronic devices and consequently their charge. Self- assembled monolayers (SAMs) are a versatile tool for tuning the properties of metallic, semi-conducting, and insulating surfaces. Within this context, OFETs represent excellent instruments for measuring the electrical properties of the SAMs in a Metal/SAM/OS junction. Our experimental approach, named Charge Injection Organic-Gauge (CIOG), uses OFET in a charge-injection controlled regime. The CIOG sensitivity has been extensively demonstrated on different homologous self-assembling molecules that differ in either chain length or in anchor/terminal group. One of the latest branch of organic electronics is the so-called “bio-electronics” that makes use of electronic devices to encompass interests of the medical science, such as biosensors, biotransducers etc. As a result, the second part of this thesis deals with the realization of an electronic transducer based on water stable OFET. In particular, the conventional bottom gate/bottom contact configuration is replaced by a top gate architecture in which the electrolyte ensures the electrical connection between gate and the semiconductor layer. This configuration is termed Electrolyte-Gated Field-Effect Transistor (EGOFET). The functionalization of the top electrode is the sensing core of this (bio- )transducer allowing the detection of dopamine and other biomarkers (i.e. interleukins) with ultra-low sensitivity.
    04/2014, Degree: PhD, Supervisor: Fabio Biscarini