The generation of NOVEL MATERIALS TO HARNESS THE POWER OF BIOLOGICAL SYSTEMS as primary sensors is extremely attractive: rapid cellular signal treatment and amplification by cellular algorithms provides high specificity and sensitivity. ELECTRICAL ACTIVITIES FORM THE BASE OF KEY EVENTS such as brain activity, heart beat or hormone secretion and can be connected to command lines for actuators. Signals are precisely shaped over time via the in- and outflow of distinct ion species through specific plasma membrane channels.

Development of HUMAN “ORGAN-ON-CHIP” DEVICES provides unique opportunities for drug screening and diagnostics on patient derived stem cells. Growth of the global Organ-On-Chip market is impeded by capturing probe/gene free “native” signals for small sample and analyte volumes. Electrophysiology could provide a very appealing solution. However, whereas imaging has gone through a revolution, electrophysiology has not evolved to the same level. Characterizing electrical activity remains complex due to expensive equipment and demanding technicity. Probe-free techniques resolving single action potentials and grouped electrical activity could bring electrophysiology to non-specialized laboratories.

FLEXIBLE ORGANIC ELECTRONICS is particularly suited for interfacing with tissues/cells as ORGANIC ELECTROCHEMICAL TRANSISTOR (OECT). Their mixed electronic/ionic conductivity decreases impedance with richer electrical recordings and local signal amplification with unprecedented signal-to-noise ratio. This should allow use not only in neuronal or cardiac cells, but also in other excitable cells with notoriously small signal amplitude, but known to be excellent sensors and involved in important chronic diseases (islet b-cells, vascular cells, eg.).

RENDERING OECTS SPECIFIC FOR DISTINCT IONS would greatly improve analytical power as did different fluorescent protein “colors” for imaging. However, existing “ion-selective electrodes” are combinations of ion selective membranes and conducting polymers. They do not combine metal ion sensing AND electronic transduction, which would increase specificity, detection limits and printability for large scale production.

WE THEREFORE PROPOSE, based also on preliminary results (i) to develop MULTIMODAL ION-SENSING POLYMERS as well as ION-SENSING POLYMER NANOSTRUCTURES, (ii) to ENGINEER OECT ARRAYS as disposable, non-invasive devices for detection of electrical cell activity and specific ion fluxes, (iii) to DEMONSTRATE THEIR POTENTIAL IN MULTIMODAL MICRO-ORGAN RECORDING of electrical cell activity and specific ion fluxes.