Biofunctionalized organic electrochemical transistors for in vitro metabolite sensing

Abstract

Event Abstract Back to Event Biofunctionalized organic electrochemical transistors for in vitro metabolite sensing Xenofon Strakosas1, Mary Donahue1, George Malliaras1 and Roison Owens1 1 Ecole des Mines de St. Etienne, Bioelectronics, France Organic bioelectronics refers to the coupling of conducting polymer based devices with biological systems, in an effort to bridge the biotic/abiotic interface[1]. Recreating a biomimetic interface on a device or electrode is one way to create a more ‘in vivo’ like environment, and also to introduce specificity via a biorecognition element. A particular advantage of the use of organic electronic materials is their chemical tunability. We have previously demonstrated a versatile method for biofunctionalisation of the conducting polymer (CP) PEDOT:PSS {poly(3,4-ethylenedioxythiophene) doped with poly(styrenesulfonate)} by adding polymers with reactive sites. We demonstrated that the electrical functionality of the CP remained unchanged, and also that the biological molecules subsequently attached, remain functional[2]. Figure 1 shows patterns of fluorescein labelled PC-12 neuron-like cells growing on PLL functionalised PEDOT:PSS patterns. These functionalised materials have been incorporated into a CP device, namely the organic electrochemical transistor (OECT) which has been successfully used to interface with biological systems[3]. The OECT has been developed for in vitro toxicology purposes to monitor the integrity of cell layers before and after addition of pathogens and toxins, in a manner analogous to electrical impedance spectroscopy[4]. In parallel, the OECT has also been used as a sensor capable of continuously detecting low concentrations of a variety of physiologically relevant metabolites[5]. During redox cycles, the metabolic analyte (e.g. glucose or lactate) and its corresponding enzyme (glucose oxidase or lactate oxidase) react, resulting in the transfer of an electron through a mediator (hydrogen peroxide) to the gate electrode. In the current work, the OECT is functionalised with redox enzymes to allow direct monitoring of metabolite release from complex media in live cell cultures. Common issues related to electrochemical sensors, such as background interference from components of the media, and diffusion of hydrogen peroxide are solved. In addition stability and reliability of the devices for long term operation are demonstrated. The described sensing platform represents a significant step towards the realization of highly sensitive sensors for metabolite detection for in vitro and in vivo applications (e.g. for implantable neural probes).