Exploring the potential of phosphorene and arsenene in plasmonic and 2D nanomaterial-based biosensing: from fundamentals to applications

Two-dimensional nanomaterials such as phosphorene and arsenene have emerged as transformative platforms for next-generation biosensing, owing to their exceptional electronic, optical, and mechanical properties. Phosphorene, derived from black phosphorus, offers a tunable direct bandgap, high carrier mobility, and strong anisotropy, enabling highly sensitive and rapid detection of biomolecular interactions through variations in conductivity, photoluminescence, and strain. Arsenene, a structurally analogous 2D allotrope of arsenic, exhibits comparable advantages, including a direct bandgap and pronounced light-matter coupling, which facilitate precise and label-free detection across optical, electrochemical, and field-effect transistor platforms. Recent advances in plasmonic coupling, surface functionalization, and hybrid nanostructure engineering have further expanded their versatility, enabling the development of multimodal and sensor-fusion approaches that integrate electronic and photonic responses for enhanced signal transduction. This review provides a comprehensive overview of the fundamental properties, synthesis strategies, and biosensing mechanisms of phosphorene and arsenene, linking their structure-property relationships to device-level performance. We also discuss challenges related to stability, large-scale fabrication, and integration into practical diagnostic, environmental, and food-safety platforms. Overall, these 2D pnictogen nanomaterials hold immense potential to advance plasmonic and multimodal biosensing technologies, paving the way toward intelligent and adaptive next-generation diagnostic systems.