Highly sensitive and selective optical detection of lead(ii) using a label-free fluorescent aptasensor. Issue 93 (20th September 2016)

• Record Type: Journal Article
• Authors: Huang, Yafei; Yan, Jiao; Fang, Zongzhuang; Zhang, Chenghui; Bai, Wenhui; Yan, Mengmeng; Zhu, Chao; Gao, Chengguo; Chen, Ailiang
• Is Part Of: RSC advances. Volume 6:Issue 93(2016)
• Page Start: 90300
• Page End: 90304
• Publication Date: 2016-09-20
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c6ra15750e
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : Configurations and measurement principles of a label-free fluorescence aptamer-based PG assay for Pb 2+ detection. Abstract : Lead (Pb) is a heavy metal that does great harm to human bodies through its accumulation in the food chain. It remains a challenge to use environment-friendly and biocompatible materials to sensitively detect lead in organisms and aquatic ecosystems. To achieve highly sensitive and selective Pb 2+ detection, a sensor based on ultra-sensitive double-stranded DNA (dsDNA) specific dye PicoGreen and label-free oligonucleotides was reported. The principle of this method is that the Pb 2+ induced a structural change of G-rich thrombin aptamer from random coil to G-quadruplex, which prevented its binding to its complementary sequences to form dsDNA and caused a fluorescence intensity decrease with PicoGreen. The results showed that this method satisfied the requirement of the maximum residue limit (MRL) of Pb 2+ and could detect Pb 2+ at a lowest concentration of 1 ng mL −1 within a dynamic range of six orders of magnitude. Since the aptamer was highly specific, this method showed high Pb 2+ selectivity against eight other metals. Finally, the proposed assay was successfully validated by determining Pb 2+ in water samples.