A Resonance Energy Transfer between Chemiluminescent Donors and Luminescent Quantum‐Dots as Acceptors (CRET)

Abstract

Fluorescence resonance energy transfer (FRET) is a powerful technique for probing very small changes in the distance between donor and acceptor fluorophores, and is ideal for the sensitive detection of molecular binding events and changes in protein conformation in response to interactions with a particular target molecule or to changes in the solution environment. In recent years, luminescent semiconductor nanocrystals (also called quantum dots, QDs) have been favorably adopted in the FRET-based studies, such as deriving QD-protein-conjugate configuration, [1] QD-protein sensing assemblies, [2,3] photochromic switching, [4] photodynamic medical therapy, [5] and probing DNA replication and telomerization.[6] This success is due to the unique sizedependent physical and chemical characteristics of QDs. QDs were applied to FRET as both donors [7][8][9][10] and acceptors, [11][12][13] and some of the advantages offered compared to conventional dyes include sharp and symmetrical emission spectra, high quantum yield (QY), good chemical and photo stability, and size-dependent emission-wavelength tunability. Recently, QDs as acceptors were successfully used in bioluminescence resonance energy transfer (BRET).[14]As with any fluorescence technique, however, photobleaching and autofluorescence limit the usefulness of FRET. Herein we report a resonance energy transfer between chemiluminescent donors and QDs as acceptors, which is called chemiluminescence (CL) resonance energy transfer (CRET), and is similar to BRET. [14][15][16][17][18][19] CRET involves nonradiative (dipole-dipole) transfer of energy from a chemiluminescent donor to a suitable acceptor molecule. In contrast to FRET, CRET occurs by the oxidation of a luminescent substrate without an excitation source. In our system, we chose the luminol/hydrogen peroxide CL reaction catalyzed by horseradish peroxidase (HRP) because this is one of the most sensitive CL reactions. In capillary electrophoresis with CL detection, the detection limit of HRP was below 10 À19 mol

Lanthanide Complexes and Quantum Dots: A Bright Wedding for Resonance Energy Transfer

“…[90][91][92] However, the drawback of short-lived donor excited states can be overcome by using LLCs as donors, which usually possess very long-lived luminescence (up to ms). Besides applications dealing with bioluminescence resonance energy transfer (BRET), [93][94][95][96] an efficient possibility of energy transfer to QDs was found to involve LLCs as donors. [97][98][99][100][101][102] We will first outline some of our results with LLC to QD FRET and then present an example of a clinically relevant immunoassay using that method.…”

New Horizons for Diagnostics and Therapeutic Applications of Graphene and Graphene Oxide

“…[ 62 ] In contrast to FRET, chemiluminescence resonance energy transfer (CRET) occurs via the specifi c oxidation of a luminescent substrate during chemiluminescence (CL) reaction without an external excitation source. [ 52 ] Lee and co-workers designed a graphene-based CRET platform for homogeneous immunoassay of C-reactive protein (CRP), a key marker for human infl ammation and cardiovascular diseases, using a luminol/hydrogen peroxide CL reaction catalyzed by horseradish peroxidase. [ 53 ] Figure 1 .…”

Simple Chemiluminescence Aptasensors Based on Resonance Energy Transfer

“…1). 29 In both probe designs, once the target was introduced, it was recognized and captured by its aptamer part in DNA2, and the formation of the adenosine/aptamer complex further led to a breakdown of the DNA/aptamer duplex. The chemiluminescence responses before and after target recognition were compared with the probes, together with free luminol molecules (Fig.…”

“…24 This leads to the requirement of complex instrumentation and a relatively high background signal; also the ease of the application and sensitivity are compromised. Alternatively, the donor energy may also come from luminescence chemical reactions, as chemiluminescence (CL), [25][26][27][28][29] with related FRET systems, known as chemiluminescence resonance energy transfer (CRET). 29,30 In this kind of scheme, no external excitation is required, and both the instrumentations and analytical procedure can be greatly simplified.…”

“…In most of reported CRET systems, fluorescent acceptors are employed. 25,29,30 One common problem in these systems is the presence of luminescence signals both before and after recognition, either in the form of chemiluminescence or the re-emitted fluorescence; also wavelength-resolving instruments (as spectrophotometers) are required to read out the shift of the emitted peaks. 22 Contrary to the fluorescent acceptors, "silent acceptors" or quenchers also work in CRET systems.…”