High Resolution Optical Recording of Bioelectric Signals Using Electrochromic Materials

Studying electrical signals in biological cells is vital to advancing our understanding of biological phenomena. Non-invasive methods with high spatial and temporal resolution are essential for such studies; they can, for example, be used to uncover how a network of interconnected neurons transmits and processes information. Existing optical recording techniques, such as voltage-sensitive fluorescent probes, are already used to measure neuronal activity; however, these methods often suffer from photobleaching and phototoxicity and are therefore limited in their ability to monitor electrical activity over long periods of time. Electrochromic optical recording (ECORE) is a technique which uses the electrochromic properties of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) in order to study bioelectric signals. It represents a non-invasive and highly flexible method of detecting these signals while also enabling their long-term recording. Here, we report on our work to increase the spatial resolution of ECORE by incorporating a microscope objective lens into our setup. Improved spatial resolution will enable us to probe local regions of cells of interest and enable us to study these cells in further detail, complementing the benefits already presented by ECORE.