http://dx.doi.org/10.1016/j.bios.2012.08.060">
 

Document Type

Journal Article

Department/Unit

Department of Chemistry

Title

Label-free detection of sub-nanomolar lead(II) ions in aqueous solution using a metal-based luminescent switch-on probe

Language

English

Abstract

A label-free oligonucleotide-based luminescent switch-on assay has been developed for the selective detection of sub-nanomolar Pb2+ ions in aqueous solution and real water samples. An iridium(III) complex was employed as a G-quadruplex specific luminescent probe and a guanine rich DNA (PS2.M, 5'-GTG3TAG3CG3T2G2-3') was employed as recognition unit for Pb2+ ions. The PS2.M exists in a single-stranded conformation in the absence of Pb2+ ions, and the weak binding of the iridium(III) probe to ssDNA results in a weak luminescence signal. Upon binding to Pb2+ ions, the single-stranded DNA sequence (PS2.M) is induced into a G-quadruplex conformation, which greatly enhances the luminescence emission of the iridium(III) probe. The assay can detect Pb2+ ions in aqueous media with a limit of detection of 600pM. It also exhibits good selectivity for Pb2+ ions over other heavy metal ions. Furthermore, the application of the assay for the detection of Pb2+ ions in spiked river water samples has been demonstrated. © 2012 Elsevier B.V.

Keywords

G-quadruplex, Iridium(III) complex, Label-free detection, Lead(II) ion, Luminescent probe

Publication Date

2013

Source Publication Title

Biosensors and Bioelectronics

Volume

41

Start Page

871

End Page

874

Publisher

Elsevier

ISSN (print)

09565663

ISSN (electronic)

18734235

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