An ECL biosensor for sensitive detection of concanavalin A based on the ECL quenching of Ru complex by MoS2 nanoflower

- PTCA and Au NPs functionalized Ru(dcbpy)32+ exhibited greatly enhanced ECL signal.
- MoS2 NF as new ECL quencher could efficiently quench ECL signal of Ru complex.
- The new ECL biosensor exhibited good performance for the detection of Con A.

A novel signal-off electrochemiluminescence (ECL) biosensor was constructed for concanavalin A (Con A) detection based on the ECL quenching of Ru complex by MoS2 nanoflower (MoS2 NF). In brief, PTCA-Ru-Au NPs as matrix was dropped on the electrode to immobilize phenoxy dextran (DexP) through π-π interaction, where 3,4,9,10-perylenetetracarboxylic acid (PTCA) and Au nanoparticles (Au NPs) could greatly increase the luminous efficiency of Tris (2,2′-bipyridyl-4,4′-dicarboxylato) ruthenium(II) (Ru(dcbpy)32+). Then, DexP as recognition element was bonded with Con A via specific carbohydrate-Con A interaction. Finally, the MoS2 NF-multi-walled carbon nanotubes (MWCNT)-DexP as quenching probe of ECL signal was combined with Con A to successfully fabricate a sandwich type ECL biosensor. Importantly, MoS2 NF as a new ECL quencher showed high ECL quenching efficiency toward Ru complex. Under the optimum detection conditions, a wide liner range of 1.0 pg/mL to 100 ng/mL was achieved with relatively low detection limit of 0.3 pg/mL.