Electrochemiluminescence energy transfer-promoted ultrasensitive immunoassay using near-infrared-emitting CdSeTe/CdS/ZnS quantum dots and gold nanorods

Abstract

The marriage of energy transfer with electrochemiluminescence has produced a new technology named electrochemiluminescence energy transfer (ECL-ET), which can realize effective and sensitive detection of biomolecules. To obtain optimal ECL-ET efficiency, perfect energy overlapped donor/acceptor pair is of great importance. Herein, we present a sensitive ECL-ET based immunosensor for the detection of tumor markers, using energy tunable CdSeTe/CdS/ZnS double shell quantum dots (QDs) and gold nanorods (GNRs) as the donor and acceptor, respectively. Firstly a facile microwave-assisted strategy for the synthesis of green- to near-infrared-emitting CdSeTe/CdS/ZnS QDs with time- and component-tunable photoluminescence was proposed. And, on the basis of the adjustable optical properties of both CdSeTe/CdS/ZnS QDs and GNRs, excellent overlap between donor emission and acceptor absorption can be obtained to ensure effective ECL-ET quenching, thus improving the sensing sensitivity. This method represents a novel approach for versatile detection of biomolecules at low concentrations.

Turn-on near-infrared electrochemiluminescence sensing of thrombin based on resonance energy transfer between CdTe/CdS core small /shell thick quantum dots and gold nanorods

“…Subsequently, the immobilization of cDNA (curve c) and BSA (curve d) resulted in the great increase of R et value due to their insulating properties (Jie et al, 2008). However, obviously decreased R et could be observed after the pDNA-AuNRs bioconjugates were assembled onto the electrode (curve e), originating from the excellent conductivity of AuNRs (Li et al, 2013). These results were consistent with the fact that the electrode was fabricated as expected.…”

“…Notably, gold nanorods (AuNRs) with distinctive shapedependent surface plasmon resonance are highly absorbent of light in the NIR region and can act as an acceptor by absorbing the NIR emission . Inspired by this, a NECL protocol involving ECL-RET from double shelled CdSeTe/CdS/ZnS QDs to AuNRs was reported (Li et al, 2013).…”

High-efficiency CdTe/CdS core/shell nanocrystals in water enabled by photo-induced colloidal hetero-epitaxy of CdS shelling at room temperature

“…For CdTe QDs, the closest match is CdS, which has a 3.6% lattice mismatch [25]. This should be compared, for instance, with ZnS, for which the mismatch is 16.5% [26][27][28]. Therefore, for CdTe, CdS is one of the most promising capping materials.…”

Signal Amplification for Highly Sensitive Immunosensing

“…In such a case, the nanoparticles act as both a solid carrier to load a large number of reporters/markers and labels to amplify the CL signal for the protein detection. Based on mesoporous SiO 2 -coated CNTs-QDs nanocomposites and ECL energy transfer (ECL-ET) technology, Zhu's group [37] (Fig. 10).…”