Electrochemiluminescence resonance energy transfer biosensor between the glucose functionalized MnO 2 and g-C 3 N 4 nanocomposites for ultrasensitive detection of concanavalin A.

An electrochemiluminescence (ECL) analytical platform was initially proposed based on the electrochemiluminescence resonance energy transfer (ECL-RET) mechanism for ultrasensitive detection of Concanavalin A (Con A). In this protocol, the glucose functionalized carboxylic g-C3 N4 nanosheets (g-C3 N4 -COOH@Glu) and MnO2 nanoparticles covered carboxylic multi-wall carbon nanotubes (BSA@MnO2 -MWCNTs-COOH@Glu) were synthesized and acted as ECL-RET electron donor and acceptor, respectively. Herein, glucose was served as the recognition element for binding Con A and MWCNTs was utilized as the carrier materials for loading MnO2 . When the quenching probe BSA@MnO2 -MWCNTs-COOH@Glu was incubated onto the modified electrodes via the specific carbohydrate-Con A interaction, the ECL signals of g-C3 N4 -COOH@Glu which used S2 O8 2- as its coreactant have drastically declined. Under optimum conditions, this biosensor performed a sensitive detection of the Con A ranging from 1 × 10-5 to 1 × 104 ng/mL with a detection limit of 2.2 fg/mL (S/N = 3). Moreover, favorable analytical outcomes for detecion Con A in actual serum samples were obtained, exhibiting huge applications in clinical diagnosis of this assay.