Visual and On-site Detection of Mercury(II) Ions on Lateral Flow Strips Using DNA-functionalized Gold Nanoparticles

摘要

A test strip for detection of Hg~(2+) in aqueous solution based on the DNA-functionalized gold nanoparticles (DNA-AuNPs) was developed and evaluated. When Hg~(2+) ions were introduced, the biotinylated DNA_(2) hybridized with thiolated DNA_(1) functionalized on the AuNPs (DNA_(1)-AuNPs) to form mismatch complexes through thymine-Hg~(2+)-thymine (T-Hg~(2+)-T) coordination. The formed mismatch complexes and excess DNA_(1)-AuNPs could be captured on the test line formed by streptavidin and the control line formed by DNA_(3)-BSA, respectively. Two red lines appeared due to the accumulation of AuNPs, enabling visual detection of Hg~(2+) with a detection limit of about 6 nM. The assay results can be obtained within 5 min. The results show that the test strip has excellent sensitivity and selectivity for detection of Hg~(2+); thus it holds a great potential for rapid, on-site and real time detection of Hg~(2+).