A hemin/G-quadruplex nanostructure that is immobilized on CdS quantum dots (QDs) associated with an electrode leads, in the presence of luminol, H 2 O 2 , and triethanolamine as an electron donor, to the generation of photocurrents with no external irradiation of the QDs. The hemin/Gquadruplex-catalyzed generation of chemiluminescence leads to the chemiluminescence resonance energy transfer (CRET) to the QDs, resulting in the photoexcitation of the QDs and the generation of electron−hole pairs. The transfer of the conduction-band electrons to the electrode, and the concomitant scavenging of the valence-band holes by the triethanolamine electron donor result in the generation of photocurrents. The CRETstimulated generation of photocurrents is applied to sense DNA by the labeling of the probe−analyte complex with a hemin/G-quadruple, and is also implemented to follow the activity of glucose oxidase and to sense glucose, by the labeling of the enzyme with the hemin/G-quadruplex catalyst.

Hemin/G-quadruplex catalyzes the H(2)O(2)-mediated oxidation of Amplex Red to the fluorescent product resorufin. This process is implemented to develop hairpin nucleic acid structures for the detection of DNA, to probe the catalytic activity of glucose oxidase, to use the thrombin-aptamer complex as a catalytic readout structure, and to quantitatively analyze telomere chain composition.

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.