A Self-Assembled G-Quadruplex/Hemin DNAzyme-Driven DNA Walker Strategy for Sensitive and Rapid Detection of Lead Ions Based on Rolling Circle Amplification.

ABSTRACT: Herein, a sensitive biosensor is constructed based on a novel rolling circle amplification (RCA) for colorimetric quantification of lead ion (Pb²⁺). At the detection system, GR5 DNAzymes are modified on the surface of an immunomagnetic bead, and Pb²⁺ is captured by the aptamer, inducing the disintegration of the GR5 DNAzyme and the release of the DNA walker. After the introduction of the template DNA, T4 DNA ligase, and phi29 DNA polymerase, an RCA is initiated for the sensitivity improvement of this method. Moreover, a G4-hemin DNAzyme is formed as a colorimetric signal, owing to its peroxide-like activity to catalyze the TMB-H₂O₂ substrate. Under the optimized conditions, the limit of detection (LOD) of this fabricated biosensor could reach 3.3

SUBMITTER: Wang Y 

PROVIDER: S-EPMC10452914 | biostudies-literature | 2023 Jul

REPOSITORIES: biostudies-literature