Photo-Induced Electron Transfer-Based Versatile Platform with G-Quadruplex/Hemin Complex as Quencher for Construction of DNA Logic Circuits.

G-quadruplex has been developed as an innovator for analytical chemistry and biomedicine due to its vibrant binding activity, structural polymorphism, and critical roles in biological regulation. Herein, a simple but versatile platform was obtained by integrating split G-quadruplex and fluorophore into a molecular beacon, where the photoinduced electron transfer could occur when the fluorophore approached the preformed G-quadruplex/hemin complexes. Such design subtly combined the G4 disruption-induced fluorescent turn-on strategy and the photoinduced electron transfer property into one platform for constructing the logic circuits. On the basis of such a universal platform, a series of binary logic gates (OR, INHIBIT, AND, and XOR), a combinatorial gate (INHIBIT-OR), and even a complex logic operation for discrimination of multiples of three from natural numbers less than ten have been successfully achieved only by employing such platform as work unit and single-strand DNAs as inputs. The set-reset function of this platform could be realized by alternatively introducing blocking and releasing strands. In addition, this platform could operate in a biological matrix stably and precisely. Therefore, such a universal platform lays the foundation for complicating the logic systems, realizing the biocomputing and also points out a new direction for target detection.