Molecular imprinting electrochemiluminescence sensor based on nitrogen-doped carbon quantum dots /Ru(bpy)₃@SiO₂ for...

An electrochemiluminescence (ECL) sensor based on molecular imprinting polymer and SiO₂ nanoparticles loaded Ru(bpy)₃ and nitrogen-doped carbon quantum dots (NCQDs) is constructed for citrinin detection. The Ru(bpy)₃ acts as ECL emitter, and the NCQDs cooperate with tri-n-propylamine (TPA) in solution as a coreactant to facilitate the luminescence. The citrinin imprinted poly(p-aminothiophenol) film is deposited on the surface of the luminophore by electrochemical method, which can immobilize the luminophore besides recognizing the target. The obtained ECL sensor exhibits high sensitivity, stability, and reproducibility. The change of ECL intensity and the logarithm of citrinin concentration display a good linear relationship in the range 1.0 to 100 pg mL^-1, and the detection limit is 5 fg mL^-1. When it is applied to the detection of citrinin contents in food sample (i.e., rice and millet) solutions, the RSD is less than 6.1%, and the recoveries for spiked standards range from 95.5 to 102.0%. Hence, this work provides a promising alternative for citrinin detection.