Direct visualization of environment-stimulated electrical signals in plants using low-drift dry electrodes

Abstract

Plants use electrical signals to transmit information. Understanding how these signals are generated and propagated is needed to figure out sensing and response mechanisms. However, bioelectronic interfaces for plants are often constrained by limited electrode density or unstable interfaces, leading to a low spatial resolution and a signal drift that restricts the spatiotemporal visualization of electrical activities. Here we report a low-drift electrode array that can be used to visualize environment-stimulated electrical signals in plants. The electrode array is based on a dry and conductive composite material made from an MXene and a pressure-sensitive adhesive, which is placed on a gold/chromium/polydimethylsiloxane thin film. We use a bioelectronic model to optimize electrode configuration and interpret mapping data, and show that the platform can provide a real-time visualization of electrical signal propagation in the plant Mimosa pudica. In particular, we directly observe electrical waves travelling along the petiole under diverse stimuli, and provide a quantitative analysis of M. pudica signalling patterns in dynamic environments. We also show that the platform can spatiotemporally resolve wound-elicited electrical waves in Arabidopsis mutants and the crop species choy sum. Low-drift electrode arrays—based on a dry and conductive composite material made from an MXene and a pressure-sensitive adhesive—can be used to spatiotemporally map electrical signal propagation in plants such as Mimosa pudica.