Biocompatibility studies of functionalized regioregular poly(3-hexylthiophene) layers for sensing applications.
ABSTRACT There is a significant medical and biological need for cheap disposable analytical sensing devices, which can be used in clinical settings or medical research. Organic electronics based on polymeric materials, being suitable for large-area, low-cost, flexible, and maybe even disposable electronics, could satisfy this need in a very elegant way. Unfortunately, the ensurance of biocompatibility and biofunctionalization of conducting and semiconducting polymers is still often lacking. In the present study, we concentrate on one of the most promising polymeric materials, regioregular poly(3-hexylthiophene) (P3HT), being both a reasonably conducting and optically active polymer. To overcome biocompatibility problems, protein-based coatings and oxygen-plasma treatments are performed to enable growth of adherent living cells on those modified surfaces. For our studies, the polymer material is spun or casted onto glass substrates under an inert nitrogen atmosphere. The toxic solvents are removed by thermal treatment with subsequent application of the coating or functionalizing materials. Cell-growth studies and adhesion experiments on the modified P3HT thin-film layers are carried out with mouse fibroblasts. This work demonstrates the biocompatibility and biofunctionalization of an active semiconducting organic polymer, hence opening new possibilities in the realization of biomedical test systems based on organic biosensors in life sciences.
- SourceAvailable from: diee.unica.it[show abstract] [hide abstract]
ABSTRACT: Organic ion-sensitive field-effect transistors assembled on flexible plastic films have been fabricated. A thin Mylar™ foil acts both as substrate and gate dielectric. The active layer is vacuum-sublimed on one side of the foil, prepatterned with bottom-contact Au source and drain electrodes. The opposite side of the insulating film is in contact with an electrolytic solution that together with a reference electrode forms an ionic gate. A sensitivity of the device to the pH of the electrolyte solution has been observed. Thanks to the flexibility of the substrate and the low cost of the employed technology, this device opens the way for flexible sensors that can be employed in a variety of innovative applications.Applied Physics Letters 03/2005; 86(10):103512-103512-3. · 3.79 Impact Factor
- [show abstract] [hide abstract]
ABSTRACT: We have constructed and characterised a glucose sensor using glucose oxidase (GOD) covalently attached to carboxylic acid polyethyleneglycol (PEG), called (PEG–GOD). This modified enzyme was entrapped afterwards within poly(3,4-ethylenedioxythiophene) (PEDT) films electrogenerated on glassy carbon (GC) electrodes. The composite (PEG–GOD/PEDT) film is more porous than the film without enzyme (PEDT+PEG). Data from electrochemical quartz microbalance (ECQM) and pH-stat experiments indicate a good relative activity of the modified enzyme, ca. 12–15%. Amperometric measurements, using ferrocenemethanol as the redox mediator, confirms that the modified enzyme is catalytically active. The effect of film thickness was also investigated. The sensitivities were quite similar for modified-GOD electrodes (ca. 3 mA cm−2 M−1) and unmodified-GOD electrodes (ca. 2.7 mA cm−2 M−1) but a better stability was obtained with modified PEG–GOD electrodes.Journal of Electroanalytical Chemistry. 01/2001;
- [show abstract] [hide abstract]
ABSTRACT: Conducting organic polymers have found two main kinds of application in electronics so far: as materials for construction of various devices and as selective layers in chemical sensors. In either case, interaction with ambient gases is critical. It may compromise the performance of a device based on conducting polymers, whereas it is beneficial in a sensor. Conductivity has been the primary property of interest. Work function--related to conductivity, but in principle a different property--has received only scant attention. Our aim here is to discuss the usability of conducting polymers in both types of electronic applications in light of these two parameters.Nature Material 02/2003; 2(1):19-24. · 35.75 Impact Factor