Electrochemiluminescence resonance energy transfer system between GNRs and Ru(bpy)32+: Application in magnetic aptasensor for β-amyloid

Publication date: 15 February 2018
Source:Biosensors and Bioelectronics, Volume 100
Author(s): Hong Ke, Haifeng Sha, Yinfang Wang, Weiwei Guo, Xin Zhang, Zhiming Wang, Chusen Huang, Nengqin Jia
Electrochemiluminescent (ECL) assay has gradually drawn increasing interest in the biomedical analysis. This paper proposed a new methodology for ultrasensitive and facile detection of Alzheimer's disease marker β-amyloid (Aβ) by fabricating a sandwich-type ECL sensing platform. Herein, electrochemiluminescence resonance energy transfer (ECL-RET) was employed to determine Aβ concentration, which can be attributed to the quenching effect from RET between Ru(bpy)3²⁺ and gold nanorods (GNRs) acting as ECL-RET electron donor and acceptor, respectively. In this protocol, mesoporous carbon nanospheres were adopted to immobilize ECL reactant Ru(bpy)3²⁺ and antibody via nafion to acquire the RET donor nanocomposites (MOCs/nafion/Ru(bpy)3²⁺/antibody), which were tightly interconnected with epoxy group functionalized Fe3O4 nanoparticles. It is of vital importance that GNRs with exquisite rod shape were synthesized and exhibited a typical absorption peak at 650nm to quench ECL signal of Ru(bpy)3²⁺ effectively. In addition, the ECL emission decreased linearly with the logarithm of Aβ concentration in a wide linear range from 1.0 × 10⁻⁵ to 100ng/mL with a detection limit of 4.2 × 10⁻⁶ng/mL. Furthermore, distinctive and desirable properties were verified to declare the promise for being applicable to analyze the Aβ content in real Alzheimer's cerebrospinal fluid samples with satisfactory results.



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