Photoelectrochemical Biosensors Without External Irradiation: Probing Enzyme Activities and DNA Sensing Using Hemin/G-Quadruplex-Stimulated Chemiluminescence Resonance Energy Transfer (CRET) Generation of Photocurrents

Abstract

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.

A novel photoelectrochemical sensor based on photocathode of PbS quantum dots utilizing catalase mimetics of bio-bar-coded platinum nanoparticles/G-quadruplex/hemin for signal amplification

“…The detection limit was 0.08 pM. This detection limit was not only much lower than other assays for the detection of target DNA with different measurement protocols such as electrochemistry (Wan et al, 2014;Cui et al, 2014;Dharuman and Hahn, 2008), fluorimetry Sun et al, 2014;Sharon et al, 2010;Zhang et al, 2013), colorimetry (Nie et al, 2014), but also much lower than those PEC detection with different amplification strategies (Golub et al, 2012;Liu et al, 2006Liu et al, , 2008. The detailed comparison for different methods is listed in Table S2.…”

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.…”

CdS/MoS 2 heterojunction-based photoelectrochemical DNA biosensor via enhanced chemiluminescence excitation

“…425 nm (curve a), whereas CdS QDs showed a broad absorption below 500 nm (curve b). Apparently, the CL spectrum of luminol oxidation and the absorption spectrum of CdS QDs were highly overlapped in a wide wavelength range, demonstrating luminol-based chemiluminescence as excitation light could apply to the construction of photoelectrochemical biosensor (Golub et al, 2012).…”