A Bioinspired sensory-CAPode with Dual Functionality: Logic Gate and Real-Time Biosensing

Ionic devices, specifically electrochemical capacitor diode (CAPode) and gated variable electrochemical capacitor diode (G-CAPode), represent an innovative paradigm for energy-efficient and biomimetic next-generation logic computing. Their compactness and integrability render them ideal for ion-transistor circuits, facilitating the delivery, regulation, and pattern establishment of ionic and biomolecular signals. Here, we engineered a biocompatible sensory-electrode to develop a potential-driven ionologic platform, capable of combining unidirectional current and sensing in a sensory-CAPode system. This precise control of unidirectional response is achieved via an asymmetric electrode assembly, enabling redox reactions on a Ti-wire electrode surface with tunable overpotential. The counter electrode with high double-layer capacitance balances the faradaic reactions on the wire electrode. The fabricated CAPode exhibits excellent rectification capability and electrochemical performance, demonstrating high efficiency in a half-wave rectifier. Furthermore, ionologic devices are demonstrated as ion-sensitive systems for real-time monitoring of protons and glutathione (GSH) molecules, serving as a model system that mimics physiological conditions within tumor tissues (sensory-CAPode). The developed biocompatible electrode offers high sensitivity for real-time GSH monitoring in simulated physiological environments, making it a potential tool for early disease diagnosis and personalized healthcare. The combined logic gate and sensory functionality may enable logic biointerfacing and AI aided neuromodulation in future.