Detection of metal ions (Cu2+, Hg2+) and cocaine by using ligation DNAzyme machinery.
The Cu(2+)-dependent ligation DNAzyme is implemented as a biocatalyst for the colorimetric or chemiluminescence detection of Cu(2+) ions, Hg(2+) ions, or cocaine. These sensing platforms are based on the structural tailoring of the sequence of the Cu(2+)-dependent ligation DNAzyme for specific analytes. The tethering of a subunit of the hemin/G-quadruplex DNAzyme to the ligation DNAzyme sequence, and the incorporation of an imidazole-functionalized nucleic-acid sequence, which acts as a co-substrate for the ligation DNAzyme that is tethered to the complementary hemin/G-quadruplex subunit. In the presence of different analytes, Cu(2+) ions, Hg(2+) ions, or cocaine, the pretailored Cu(2+)-dependent ligation DNAzyme sequence stimulates the respective ligation process by combining the imidazole-functionalized co-substrate with the ligation DNAzyme sequence. These reactions lead to the self-assembly of stable hemin/G-quadruplex DNAzyme nanostructures that enable the colorimetric analysis of the substrate through the DNAzyme-catalyzed oxidation of 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid), ABTS(2-), by H(2)O(2) into the colored product ABTS(·-), or the chemiluminescence detection of the substrate through the DNAzyme-catalyzed oxidation of luminol by H(2)O(2). The detection limits for the sensing of Cu(2+) ions, Hg(2+) ions, and cocaine correspond to 1 nM, 10 nM and 2.5 μM, respectively. These different sensing platforms also reveal impressive selectivities.
Institute of Chemistry, The Minerva Center for Complex Biohybrid Systems, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
Fuan
F
Wang
Ron
R
Orbach
Itamar
I
Willner
D052160:Benzothiazoles; D015374:Biosensing Techniques; D003042:Cocaine / Q000032:analysis* / Q000737:chemistry; D003124:Colorimetry; D003300:Copper / Q000032:analysis* / Q000737:chemistry; D021881:DNA, Catalytic / Q000737:chemistry*; D006427:Hemin / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry; D007477:Ions / Q000032:analysis* / Q000737:chemistry*; D008026:Ligation; D008165:Luminol / Q000737:chemistry; D008628:Mercury / Q000032:analysis* / Q000737:chemistry; D008670:Metals / Q000032:analysis* / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D013451:Sulfonic Acids / Q000737:chemistry*; D013844:Thiazoles / Q000737:chemistry*
D052160:Benzothiazoles; D021881:DNA, Catalytic; D007477:Ions; D008670:Metals; D013451:Sulfonic Acids; D013844:Thiazoles; C002502:2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid; D008165:Luminol; D006427:Hemin; D003300:Copper; D006861:Hydrogen Peroxide; D008628:Mercury; D003042:Cocaine