Polyaziridine‐Encapsulated Phosphorene‐Incorporated Flexible 3D Porous Graphene for Multimodal Sensing and Energy Storage Applications

Abstract Heteroatom‐incorporated graphene represents a prominent family of materials utilized as active electrodes for multimodal sensing and energy storage applications. Herein, a novel polyaziridine‐encapsulated phosphorene (PEP)‐incorporated flexible 3D porous graphene (3DPG) electrode is developed using facile, cost‐effective laser writing, and drop‐casting techniques. Owing to the excellent electrochemical characteristics and surface functionality of the highly stable PEP, the fabricated PEP/3DPG is evaluated as a potential electrode for immunosensing, electrocardiogram (ECG) recording, and microsupercapacitors (MSCs). Under optimized conditions, the produced PEP/3DPG‐based carcinoembryonic immunosensor exhibits linear ranges of 0.1–700 pg mL⁻¹ and 1–100 ng mL⁻¹ with a detection limit of 0.34 pg mL⁻¹ and high selectivity. The finger touch‐based ECG sensor demonstrates a relatively low and stable impedance at the skin‐electrode interface; therefore, the signal‐to‐noise ratio of the ECG signal received from the fabricated sensor (13.5 dB) is comparable to that of conventional Ag/AgCl electrodes (13.9 dB). Besides, the highest areal capacitance of the prepared MSC reached a magnitude of 16.94 mF cm⁻², which is six times higher than that of a non‐doped 3DPG‐based MSC. These results demonstrate the effectiveness of the described fabrication procedure and the high utilization potential of the encapsulated phosphorene‐doped 3D graphene in multimodal applications.