Electrochemiluminescence resonance energy transfer biosensor between the glucose functionalized MnO2 and g-C3N4 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-C3N4 nanosheets (g-C3N4-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-C3N4-COOH@Glu which used S2O82- as its coreactant have drastically declined. Under optimum conditions, this biosensor performed a sensitive detection of the Con A ranging from 1 x 10(-5) to 1 x 10(4) 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.