Detection of specific concanavalin a based on mannose-immobilized silicon nanowire (SiNW) biosensors with tunable mannose ratios

Abstract The silicon nanowire (SiNW) biosensors were fabricated on an n-type SOI substrate with optimized nanowire width and doping concentration to enhance sensitivity. Using SiNW biosensors with similar structural and electrical characteristics, we developed a biosensor platform capable of detecting concanavalin A (Con A) through lectin–glycan interactions by precisely controlling the mannose density on the sensor surface. Mannose molecules were immobilized on the SiNW surface at controlled ratios of 0%–100%, enabling specific systematic evaluation of Con A binding. The resistance change ratio increased significantly with higher mannose ratio compared to the non-glycosylated compound, while sensors without mannose showed no measurable response. Furthermore, the negligible response to peanut agglutinin confirmed the specificity of mannose-Con A recognition. These results demonstrate that mannose-functionalized SiNW biosensors enable selective and real-time detection of lectin–glycan interactions. This approach may contribute to glycan-based disease diagnosis and biosensing applications.