G-Quadruplex Network Engineering in Ionogels: Realizing Robust Biosensing Interfaces for Plant Electrophysiology

A reliable plant-machine interface plays a substantial role in utilizing plant electrophysiology for real-time monitoring and intervention of plant physiological conditions but is still challenging to establish due to the difficult construction of stable, conformal biosensing interface between noninvasive electrodes and plants. Here, we demonstrate that under the premise of sufficient adhesive strength on smooth surfaces, the magnitude of elastic modulus is the key factor influencing the conformability of the gel electrode. Accordingly, an ionogel is specifically designed by incorporating G-quadruplexes into chemically cross-linked network. Its Young's modulus is significantly reduced, yet its toughness is enhanced, achieving robust conformal adhesion on complex plant surfaces. We show that the ionogel electrode can be leveraged to capture high-fidelity plant electrophysiological signals, exhibiting low contact impedance and a high signal-to-noise ratio, particularly providing hairy interface stability and signal authenticity under disturbances. This work advances the noninvasive recording technique of electrical signaling in plants.