Label-Free Ag+ Detection by Enhancing DNA Sensitized Tb3+ Luminescence
AbstractIn this work, the effect of Ag+ on DNA sensitized Tb3+ 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. We discovered that both poly-G and poly-T DNA have a significant emission enhancement by Ag+, while the absolute intensity is stronger with the poly-G DNA, indicating that a G-quadruplex DNA is not required for this enhancement. Using the optimized length of the G7 DNA (an oligo constituted with seven guanines), Ag+ was measured with a detection limit of 57.6 nM. The signaling kinetics, G7 DNA conformation, and the binding affinity of Tb3+ to the DNA in the presence or absence of Ag+ are also studied to reveal the mechanism of emission enhancement. This observation is useful not only for label-free detection of Ag+, but also interesting for the rational design of new biosensors using Tb3+ luminescence. View Full-Text
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Kleinke, K.; Saran, R.; Liu, J. Label-Free Ag+ Detection by Enhancing DNA Sensitized Tb3+ Luminescence. Sensors 2016, 16, 1370.
Kleinke K, Saran R, Liu J. Label-Free Ag+ Detection by Enhancing DNA Sensitized Tb3+ Luminescence. Sensors. 2016; 16(9):1370.Chicago/Turabian Style
Kleinke, Kimberly; Saran, Runjhun; Liu, Juewen. 2016. "Label-Free Ag+ Detection by Enhancing DNA Sensitized Tb3+ Luminescence." Sensors 16, no. 9: 1370.
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