An allosteric dual-DNAzyme unimolecular probe for colorimetric detection of copper(II).
An effective dual-DNAzyme-based unimolecular probe design employing intramolecular signal transduction is demonstrated. The probe is composed of three domains: a DNA-cleaving DNAzyme, a substrate, and an HRP-mimicking DNAzyme. When the probe meets its target, cleavage of the substrate by the DNA-cleaving DNAzyme activates the HRP-mimicking DNAzyme, producing a colorimetric signal. The Cu(2+)-dependent DNAzyme engineered to demonstrate this design revealed a sensitivity corresponding to 65 ppb, which is sufficient to detect Cu(2+) in drinking water. The new probe has excellent selectivity toward Cu(2+). This three-component design is simple and easy to engineer. It may provide the basis for future development of other nucleic acid-based probes for toxicological and environmental monitoring.
Yin
Bin-Cheng
BC
Laboratory of Biosystems and Microanalysis, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Meilong Road 130, Shanghai 200237, China.
Ye
Bang-Ce
BC
Tan
Weihong
W
Wang
Hui
H
Xie
Cong-Cong
CC
D000494:Allosteric Regulation; D001483:Base Sequence; D015374:Biosensing Techniques / Q000379:methods*; D003124:Colorimetry; D003300:Copper / Q000032:analysis* / Q000378:metabolism; D021881:DNA, Catalytic / Q000235:genetics / Q000378:metabolism*; D006735:Horseradish Peroxidase / Q000378:metabolism; D006801:Humans; D015202:Protein Engineering
D021881:DNA, Catalytic; D003300:Copper; D006735:Horseradish Peroxidase