Synergistic passivation of black phosphorene with both silver nanoparticles and rice husk biochar for enhanced electrochemical detection of baicalin

Recent advancements in two-dimensional materials have highlighted black phosphorene (BP) as a promising candidate for optical and electrical applications. However, its practical utility is hindered by ambient instability and limited conductivity. This study aims to solve these problems with a surface passivation strategy. Silver nanoparticles (AgNPs) and rice husk biochar (RHB) are combined to prepare a BP-based nanocomposite (RHB-BP-AgNPs). AgNPs effectively occupy oxidation sites on BP’s surface, mitigating degradation while enhancing conductivity with RHB synergy. The morphology, microstructure and chemical composition of RHB-BP-AgNPs nanocomposite was comprehensively characterized by diversified techniques. The RHB-BP-AgNPs exhibited exceptional ambient stability (>16 days) and superior electrocatalytic activity, enabling its application as a sensing platform for baicalin detection. The sensor demonstrated a wide linear response (0.007–8.0 μM), a low detection limit (5.45 nM), and high selectivity against interferents. Validation in real pharmaceutical samples yielded satisfactory recovery rates of 95.4–104.6 % with RSD from 1.27 to 2.13, underscoring practical reliability. This work not only presents a robust strategy to stabilize and functionalize BP but also advances rapid, sensitive detection methodologies for bioactive compounds in traditional medicine, bridging material innovation with analytical applications.