Designing a Biostable L-DNAzyme for Lead(II) Ion Detection in Practical Samples.

ABSTRACT: A promising biosensor for effectively lead (II) ion detection in practical applications was developed by constructing a Pb²⁺-specific L-DNAzyme, the enantiomer of the natural nucleic acid-constructed D-DNAzyme. This fluorescent sensor contains the L-enzyme strand with a quencher at the 3' end, and the L-substrate strand with a fluorophore at the 5' and a quencher at the 3' ends that formed a complex. In the presence of Pb²⁺, the L-substrate is cut into two fragments, leading to the recovery of fluorescence. The sensor shows high sensitivity and selectivity for Pb²⁺ detection with a linear response in the range of 5-100 nM and a detection limit of 3 nM in aqueous solution. Importantly, based on that L-DNAzyme consists of non-natural nucleic acids, which is insensitive to nuclease digestion, protein adsorption and D-DNA hybridization, our sensor shows specific response to Pb²⁺ in practical water and serum samples. Therefore, it is expected that our L-DNAzyme-based strategy may offer a new method for developing simple, rapid and sensitive sensors in complex systems.

SUBMITTER: Liang H 

PROVIDER: S-EPMC5650247 | biostudies-literature | 2016 Oct

REPOSITORIES: biostudies-literature