title: Ultrasensitive DNAzyme beacon for lanthanides and metal speciation.
abstract: Metal-ion detection and speciation analysis is crucial for environmental monitoring. Despite the importance of lanthanides, few sensors are available for their detection. DNAzymes have been previously used to detect divalent metals, while no analytical work was carried out for trivalent and tetravalent ions. Herein, in vitro selection was performed using a Ce(4+) salt as the target metal, and a new DNAzyme (named Ce13) with a bulged hairpin structure was isolated and characterized. Interestingly, Ce13 has almost no activity with Ce(4+) but is highly active with all trivalent lanthanides and Y(3+), serving as a general probe for rare earth metals (omitting Sc). A DNAzyme beacon was engineered detecting down to 1.7 nM Ce(3+) (240 parts per trillion), and other lanthanides showed similar sensitivity. The feasibility of metal speciation analysis was demonstrated by measuring the reduction of Ce(4+) to Ce(3+).
authors.affiliation: Department of Chemistry, Waterloo Institute for Nanotechnology , University of Waterloo 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada.
authors.forename: Po-Jung Jimmy
authors.initials: PJ
authors.lastname: Huang
authors.forename: Jenny
authors.initials: J
authors.lastname: Lin
authors.forename: Jing
authors.initials: J
authors.lastname: Cao
authors.forename: Mahsa
authors.initials: M
authors.lastname: Vazin
authors.forename: Juewen
authors.initials: J
authors.lastname: Liu
mesh_terms: D001483:Base Sequence; D002563:Cerium / Q000737:chemistry* / Q000378:metabolism; D003067:Coenzymes / Q000737:chemistry / Q000378:metabolism; D021881:DNA, Catalytic / Q000235:genetics / Q000378:metabolism*; D005240:Feasibility Studies; D015345:Oligonucleotide Probes / Q000235:genetics / Q000378:metabolism*
chemical_list: D003067:Coenzymes; D021881:DNA, Catalytic; D015345:Oligonucleotide Probes; D002563:Cerium