A Silver-Specific DNAzyme with a New Silver Aptamer and Salt-Promoted Activity.

Most RNA-cleaving DNAzymes require a metal ion to interact with the scissile phosphate for activity. Therefore, few unmodified DNAzymes work with thiophilic metals because of their low affinity for phosphate. Recently, an Ag-specific Ag10c DNAzyme was reported via in vitro selection.

Label-Free Ag⁺ Detection by Enhancing DNA Sensitized Tb(3+) Luminescence.

In this work, the effect of Ag⁺ on DNA sensitized Tb(3+) luminescence was studied initially using the Ag⁺-specific RNA-cleaving DNAzyme, Ag10c. While we expected to observe luminescence quenching by Ag⁺, a significant enhancement was produced. Based on this observation, simple DNA oligonucleotide homopolymers were used with systematically varied sequence and length.