Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7232420 | Biosensors and Bioelectronics | 2015 | 7 Pages |
Abstract
A simple and low-cost DNA sensing platform based on Pb2+-specific DNAzyme-modified microplate was successfully developed for highly sensitive monitoring of lead ion (Pb2+, one kind of toxic heavy metal ion) in the environmental samples coupling with a portable personal glucometer (PGM)-based detection mode. The detection cell was first prepared simply by means of immobilizing the DNAzyme on the streptavidin-modified microplate. Gold nanoparticle labeled with single-stranded DNA and invertase (Enz-AuNP-DNA) was utilized as the signal-transduction tag to produce PGM substrate (glucose). Upon addition of lead ion into the microplate, the substrate strand of the immobilized DNAzyme was catalytically cleaved by target Pb2+, and the newly generated single-strand DNA in the microplate could hybridize again with the single-stranded DNA on the Enz-AuNP-DNA. Accompanying with the Enz-AuNP-DNA, the carried invertase could convert sucrose into glucose. The as-produced glucose could be monitored by using a widely accessible PGM for in situ amplified digital readout. Based on Enz-AuNP-DNA amplification strategy, as low as 1.0Â pM Pb2+ could be detected under the optimal conditions. Moreover, the methodology also showed good reproducibility and high selectivity toward target Pb2+ against other metal ions because of highly specific Pb2+-dependent DNAzyme, and was applicable for monitoring Pb2+ in the naturally contaminated sewage and spiked drinking water samples.
Keywords
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
Jin Zhang, Ying Tang, Liumei Teng, Minghua Lu, Dianping Tang,