Determination of Brilliant Blue FCF by a Novel Solid-state ECL Quenching Sensor of Ru(bpy)32+-poly(sulfosalicylic acid)/GCE.

A novel solid-state electrochemiluminescence (ECL) quenching sensor was constructed for determination of brilliant blue FCF (BB FCF). Under a simple electropolymerization step, poly(sulfosalicylic acid) (PSSA) film attached luminophore Ru(bpy)32+ was successfully formed on the surface of a glass carbon electrode [Ru(bpy)32+-PSSA/GCE], which exhibited excellent ECL behavior. A high quenching effect on the ECL signal of the Ru(bpy)32+-PSSA/GCE was obtained with the presence of low concentration of BB FCF. Moreover, the quenched ECL intensity showed a linear relation within the BB FCF concentration range of 0.5 - 7 and 7 - 10 μmol/L, with a detection limit of 57 nmol/L (S/N = 3). Besides, Ru(bpy)32+-PSSA/GCE exhibited good reproducibility and was successfully applied in the practical detection of BB FCF in peppermint candy samples.