Sandwich-configuration electrochemiluminescence biosensor based on Ag nanocubes–polyamidoamine dendrimer–luminol nanocomposite for Con A detection

Abstract

A sandwich-configuration electrochemiluminescence (ECL) biosensor was constructed with Ag nanocubes–polyamidoamine dendrimer–luminol–glucose oxidase (AgNCs–PAMAM–luminol–GOx) as the signal probe for detecting concanavalin A (Con A). In brief, three-dimensional molybdenum disulfide–polyaniline (3D-MoS2–PANI) nanoflowers were prepared as the matrix for combining phenoxy functionalized dextran (DexP) via π–π interaction. Here, DexP served as a recognition element for binding Con A. Then, AgNCs–PAMAM–luminol–GOx nanocomposite was bound to the bind site of Con A through specific carbohydrate–Con A interaction, thus achieving a solid-state luminol biosensor. Herein, DexP, Con A and AgNCs–PAMAM–luminol–GOx formed a sandwich-type configuration. AgNCs–PAMAM could immobilize large amounts of luminescence reagent luminol. Importantly, AgNCs and MoS2 could catalyze H2O2 to generate abundant reactive oxygen species (ROSs), further enhancing the ECL intensity. As a result, such a sandwiched ECL biosensor exhibited two wide linear response ranges from 0.005 to 0.1ng/mL and 0.1 to 20ng/mL for Con A detection.