G‐Quadruplex‐Based Photooxidase Driven by Visible Light

Abstract

The G‐quadruplex (G4)/hemin entity has been widely used as a peroxidase‐mimic DNAzyme to catalyze the substrate oxidation with exogenous and concentrated H2O2 as oxidant for developing various devices. Herein, a G4‐based oxidase‐mimic DNAzyme that can be driven by visible light was developed. The oxidant is in situ produced by light irradiation. As a natural photosensitizer, Hypericin (Hyp) alone in solution is inactive because of aggregation. However, the binding with G4 triggers the fluorescence emission and activates Hyp to produce singlet oxygen (1O2) by energy transfer to the dissolved oxygen. Therefore, the G4/Hyp entity can serve as a photooxidase via the 1O2 pathway to catalyze the substrate oxidation. Since the G4‐bound Hyp can be excited by almost the whole range of visible light, the photooxidase should cover a wide range of photocatalytic applications. Similar to the peroxidase‐mimic DNAzyme, the G4 sequence can regulate the photooxidase activity and metal ions can serve as efficient cofactors to activate the photooxidase capacity for an inactive G4 structure. This work provides an alternative to build a versatile G4‐based photooxidase with straightforward tunability of its activity.

Functional Nucleic Acids Under Unusual Conditions

“…A G4 DNA based hybrid photooxidase, as reported by Gao et al, was recently shown to activate by visible light. [72] This photooxidase was built from a parallel G4 DNA and hypericin through an end-stacking interaction, [73] and was activated by a wide range of visible light (from 490 nm to 610 nm) via the singlet oxygen ( 1 O 2 ) pathway to catalyze the substrate oxidation. Since G4 DNA hybrid catalysts are capable of catalyzing a variety of chemical reactions, including enantioselective Michael addition reactions, asymmetric Diels-Alder reactions, and Friedel-Crafts alkylation reactions, [36] their promise should not be overlooked in the future of biochemical applications under unusual conditions.…”

“…A G4 DNA based hybrid photooxidase, as reported by Gao et al., was recently shown to activate by visible light [72] . This photooxidase was built from a parallel G4 DNA and hypericin through an end‐stacking interaction, [73] and was activated by a wide range of visible light (from 490 nm to 610 nm) via the singlet oxygen ( 1 O 2 ) pathway to catalyze the substrate oxidation.…”

Design of communication systems based on broadband sources for fiber and free space optical links

“…Since communication systems based on broadband sources have many advantages such as has been previously demonstrated in [Kim 2007, Gra 2009, Gra 2010, Kan 2014, Dim 2015, Kar 2015, Chi 2017b, Sen 2019, Gao 2019, Yeh 2019, Zho 2019, they undoubtedly offer a great opportunity for the future of optical communication both for free space and optical fiber communications.…”

“…Additionally, it offers high data rate compared to the conventional RF-based wireless technologies such as Wi-Fi and Bluetooth, thanks to its huge bandwidth [Pis 2012]. Most of the recent studies on VLC consider the LEDs as transmitter, such as [Erg 2015, Gao 2019, Li 2019a, Sin 2019, Zho 2019, Yeh 2019]. However, according to [Erg 2015], there are two main challenges in utilization of LEDs as transmitter, the limited bandwidth (Bandwidth can be extended with complex type of LEDs); and the nonlinearity (nonlinear relationship between current and optical power in LEDs becomes challenging in high data rate applications).…”

“…Optical wireless communication is an emerging field of telecommunications that uses different optoelectronic devices such as light emitting or light detecting devices. Recently, a large number of researchers as [Vuc 2009, Cho 2013, Hua 2015, Kar 2015, Li 2016, Tia 2017, Gao 2019, Yeh 2019, Zho 2019 are focusing on the development of new devices that will adapt to the next generation of broadband optical wireless communication technologies. This future evolution is based on the maturity of the broadband wireless personnel mobile and the ultra-speed fiber communication technologies.…”