Following Glucose Oxidase Activity by Chemiluminescence and Chemiluminescence Resonance Energy Transfer (CRET) Processes Involving Enzyme-DNAzyme Conjugates

Abstract

A hybrid consisting of glucose oxidase-functionalized with hemin/G-quadruplex units is used for the chemiluminescence detection of glucose. The glucose oxidase-mediated oxidation of glucose yields gluconic acid and H2O2. The latter in the presence of luminol acts as substrate for the hemin/G-quadruplex-catalyzed generation of chemiluminescence. The glucose oxidase/hemin G-quadruplex hybrid was immobilized on CdSe/ZnS quantum dots (QDs). The light generated by the hybrid, in the presence of glucose, activated a chemiluminescence resonance energy transfer process to the QDs, resulting in the luminescence of the QDs. The intensities of the luminescence of the QDs at different concentrations of glucose provided an optical means to detect glucose.

Quantum Dots in Bioanalysis: A Review of Applications across Various Platforms for Fluorescence Spectroscopy and Imaging

“…Willner's group has exploited catalytic hemin/G-quadruplex DNAzymes for the detection of DNA, metal ions, aptamer-substrate complexes, thrombin, glucose oxidase, and ATP by using QD-CRET. [142][143][144][145] The hemin/G-quadruplex DNAzyme exhibits peroxidase-like activity that can catalyze the chemiluminescent reaction between luminol and H 2 O 2 . For DNA detection, three different colors of QDs (PL at 490, 560, and 620 nm) were functionalized with three different hairpin oligonucleotide probes that were complementary to three target oligonucleotide sequences of interest.…”

DNA Switches: From Principles to Applications

“…The introduction of additional triggering stimuli, such as other metal ions (e.g., by the incorporation of synthetic bases into the DNA, ligandosides) [87] or the use of aptamer-substrate complexes, [88] could broaden the possible applications of these molecular devices. Also, the development of additional readout signals that probe the switching systems, such as chemiluminescence resonance energy transfer (CRET), [89] surface plasmon resonance (SPR), [90] and dynamic scanning-probe microscopies, could provide novel imaging tools. [91] The applications of DNA switches represent, however, major scientific and technological challenges, and the use of these systems for developing innovative photonic nanostructures, for "smart" nano-medicine, and for the controlled chemical synthesis may be envisaged.…”

Quantum Dots for Pharmaceutical and Biomedical Analysis

“…Quantitative determination of glucose can be realized from the luminescence intensity of the QDs. The detection limit of glucose was calculated to 5 mmol L −1 [131].…”