The Construction Of G-quadruplex-based DNA Logic Gate And Its Biologicalapplication

G-quadruplex, as a functional nucleic acid, has been widely used in analytical chemistry and the construction of logic gates and biosensors. In this present paper, two logic gates and one biosensor were fabricated by utilizing advantages of G-quadruplex-based fluorescent probe and DNAzyme.(1) By utilizing G-quadruplex-based fluorescent probe and DNA hybridization, an enzyme free and label free 2:1 multiplexer was designed. Our strategy is simple in operation and the cost is low without label free and enzyme free, which shows a promising application in developing biological devices in vivo.(2) Further, by combining G-quadruplex-based fluorescent probe with GO, which could adsorb ss-DNA and quench the fluorescent dye, a 1:2 demultiplexer was constructed. Based on the competition hybridization reactions between several DNA strands, we successfully performed the functions of 1:2 demultiplexer.(3) Based on peroxidase-like property of G-quadruplex-Cu(?) metalloenzyme, a colorimetric strategy for simultaneous detection of histidine and cysteine has been developed for the first time. The limit of detection for histidine and cysteine is 10 nM and 5 nM through experimental measurements, respectively. To the best of our knowledge, our method is much more sensitive with a low cost. Moreover, the operation is very simple, which meets the requirements for point-of-care detection.