Novel tri-layer self-enhanced Ru(II) complex-based nanoparicles for signal-on electrochemiluminescent aptasensor construction

The synthesis, characterization and application of a novel tri-layer self-enhanced Ru(II) complex-based electrochemiluminescence (ECL) nanoparticles for an ultrasensitive signal-on thrombin aptasensor construction was demonstrated in this work. Specifically, the tri-layer self-enhanced nanoparticle composed of Ru(II)-doped SnS2 nanoparticles (Ru(II)-SnS2 NPs) as inter-layer, polyamidoamine (PAMAM) dendrimers as inter-layer and Au nanoparticles as outer-layer (it can be abbreviated as Au-PAMAM-Ru (II)-SnS2 NPs). With the employment of the tri-layer self-enhanced Au-PAMAM-Ru(II)-SnS2 NPs as the signal-amplifying tags, a new signal amplification strategywas proposed based on the dual enhancement of the SnS2 nanoparticles and the PAMAM toward the ECL emission of the Ru(II) complex for the sandwiched ECL aptasensing fabrication by using thrombin as the model system. As expected, the prepared thrombin aptasensor showed a dynamic range from 5.0 x 10(-15) M to 1.0 x 10(-9) M with a detection limit down to the femtomolar level. Furthermore, the proposed strategy was simple and sensitive, avoiding the adding of any coreactant into working solution for signal amplification compared with traditional ECL-based assay. (C) 2016 Elsevier Ltd. All rights reserved.