title: Oligonucleotide-based fluorescence probe for sensitive and selective detection of mercury(II) in aqueous solution.
abstract: In this paper we unveil a new homogeneous assayusing TOTO-3 and the polythymine oligonucleotide T 33for the highly selective and sensitive detection of Hg (2+) in aqueous solution. The fluorescence of TOTO-3 is weak in the absence or presence of randomly coiled T 33. After T 33 interacts specifically with Hg (2+) ions through T-Hg (2+)-T bonding, however, its conformation changes to form a folded structure that preferably binds to TOTO-3. As a result, the fluorescence of a mixture of T 33 and TOTO-3 increases in the presence of Hg (2+). Our data from fluorescence polarization spectroscopy, capillary electrophoresis with laser-induced fluorescence detection, circular dichroism spectroscopy, and melting temperature measurements confirm the formation of folded T 33-Hg (2+) complexes. Under optimum conditions, the TOTO-3/T 33 probe exhibited a high selectivity (>or=265-fold) toward Hg (2+) over other metal ions, with a limit of detection of 0.6 ppb. We demonstrate the practicality of this TOTO-3/T 33 probe for the rapid determination of Hg (2+) levels in pond water and in batteries. This approach offers several advantages, including rapidity (<15 min), simplicity (label-free), and low cost.
authors: Department of Chemistry, National Taiwan University, 1, Section 4, Roosevelt Road, Taipei 106, Taiwan.
authors: Cheng-Kang
authors: CK
authors: Chiang
authors: Chih-Ching
authors: CC
authors: Huang
authors: Chi-Wei
authors: CW
authors: Liu
authors: Huan-Tsung
authors: HT
authors: Chang
mesh_terms: D001483:Base Sequence; D017931:DNA Primers; D019075:Electrophoresis, Capillary; D005456:Fluorescent Dyes / Q000737:chemistry*; D013058:Mass Spectrometry; D009841:Oligonucleotides / Q000737:chemistry*; D012680:Sensitivity and Specificity; D012996:Solutions; D014867:Water
chemical_list: D017931:DNA Primers; D005456:Fluorescent Dyes; D009841:Oligonucleotides; D012996:Solutions; D014867:Water