A sensitive electrochemiluminescent aptasensor based on perylene derivatives as a novel co-reaction accelerator for signal amplification

Abstract

Herein, a novel signal amplification strategy was designed using the perylene derivative as the co-reaction accelerator toward graphene-CdTe quantum dots (G-CdTe)/S2O82− system to construct a highly sensitive electrochemiluminescent (ECL) aptasensor for thrombin (TB) detection. Firstly, the G-CdTe nanocomposites were prepared by one-step method of in situ generating CdTe quantum dots onto the surface of the graphene oxide by using 3-mercaptopropionic acid as the CdTe QDs stabilizer. Then, a kind of perylene derivative (PTC-Lys), was synthesized by covalently binding L-lysine to 3,4,9,10-perylenetetracarboxylic acid, which was further immobilized onto the G-CdTe by the π-π* stacking and cross-linked the detection thrombin aptamer (TBA II) to obtain the TBA II/PTC-Lys/G-CdTe signal probes. It is worth pointing out that PTC-Lys acting as an efficient co-reaction accelerator interacted with the co-reactant of S2O82− rather than G-CdTe to promote the more oxidant mediators of SO4•−, which could further react with G-CdTe to produce excited state species G-CdTe* for emitting light. Compared with the G-CdTe/S2O82− ECL system, our proposed strategy with the introduction of co-reaction accelerator of PTC-Lys exhibited ultra-high sensitivity to quantify the concentration of TB from 1.0×10−7nM to 10nM with a detection limit of 34aM.