Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10429461 | Biosensors and Bioelectronics | 2011 | 4 Pages |
Abstract
An electronic DNAzyme sensor for highly sensitive detection of Pb2+ is demonstrated by coupling the significant signal enhancement of the layer-by-layer (LBL) assembled quantum dots (QDs) with Pb2+ specific DNAzymes. The presence of Pb2+ cleaves the DNAzymes and releases the biotin-modified fragments, which further hybridize with the complementary strands immobilized on the gold substrate. The streptavidin-coated, QD LBL assembled nanocomposites were captured on the gold substrate through biotin-streptavidin interactions. Subsequent electrochemical signals of the captured QDs upon acid dissolution provide quantitative information on the concentrations of Pb2+ with a dynamic range from 1 to 1000Â nM. Due to the dramatic signal amplification by the numerous QDs, subnanomolar level (0.6Â nM) of Pb2+ can be detected. The proposed sensor also shows good selectivity against other divalent metal ions and thus holds great potential for the construction of general DNAzyme-based sensing platform for the monitoring of other heavy metal ions.
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
Haixia Zhang, Bingying Jiang, Yun Xiang, Jiao Su, Yaqin Chai, Ruo Yuan,