Double-layer silver nanoparticle arrays-based localised surface plasmon resonance optical sensor for sensitive detection of concanavalin A

A localised surface plasmon resonance (LSPR) optical sensor with double-layer silver nanoparticle (Ag NP) arrays has been developed for the sensitive detection of concanavalin A (ConA). Based on the principle of carbohydrate-protein interactions, double-layer dextran capped Ag NP arrays were initially constructed. The increase of adsorption apparent mass and LSPR coupling between the two Ag NP arrays can effectively enhance the LSPR spectral shift response. Compared with the single-layer Ag NP arrays configuration, the double-layer Ag NP arrays configuration improves the limitation of detection of ConA concentration from 3.42 to ~1.14 μg/ml.