title: A facile and sensitive electrochemiluminescence biosensor for Hg2+ analysis based on a dual-function oligonucleotide probe.
abstract: In this study, a sensitive electrochemiluminescent (ECL) biosensor for the detection of Hg(2+) was easily prepared by self-assembling mercury-specific oligonucleotide on the surface of gold nanoparticles (AuNPs) modified indium tin oxide (ITO) electrode. A conformation change of the oligonucleotide from linear chain to hairpin occurs upon the binding of Hg(2+) through thymine-Hg(2+)-thymine coordination. The dual-function oligonucleotide serves as the probe to Hg(2+) but also a carrier of signal-generating molecules, [Ru(bpy)2(dppz)](BF4)2. It was estimated that one oligonucleotide was able to load with eight ECL signal molecules; a ratio of four or five oligonucleotides per gold nanoparticle was obtained basing on the calculation with surface density. Without tedious multiple-labeling procedures and special modification of oligonucleotide probe for signal transduction/amplification, a detection limit of 5.1 pM Hg(2+) was outstanding from the interference of other ten metal ions. Results of spiked water samples were in good agreement with that obtained by atomic fluorescent spectrometry.
authors.affiliation: College of Materials, Chemistry and Chemical Engineering, Chengdu University of Technology, Chengdu, Sichuan 610059, PR China. Electronic address: huangrongfu13@cdut.cn.
authors.forename: Rong-Fu
authors.initials: RF
authors.lastname: Huang
authors.affiliation: College of Materials, Chemistry and Chemical Engineering, Chengdu University of Technology, Chengdu, Sichuan 610059, PR China.
authors.forename: Hui-Xin
authors.initials: HX
authors.lastname: Liu
authors.affiliation: College of Materials, Chemistry and Chemical Engineering, Chengdu University of Technology, Chengdu, Sichuan 610059, PR China.
authors.forename: Qi-Qi
authors.initials: QQ
authors.lastname: Gai
authors.affiliation: College of Materials, Chemistry and Chemical Engineering, Chengdu University of Technology, Chengdu, Sichuan 610059, PR China.
authors.forename: Gai-Juan
authors.initials: GJ
authors.lastname: Liu
authors.affiliation: College of Materials, Chemistry and Chemical Engineering, Chengdu University of Technology, Chengdu, Sichuan 610059, PR China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Wei
mesh_terms: D001483:Base Sequence; D015374:Biosensing Techniques / Q000379:methods*; D002413:Cations, Divalent / Q000032:analysis; D004277:DNA, Single-Stranded / Q000737:chemistry*; D055664:Electrochemical Techniques / Q000379:methods; D004566:Electrodes; D006046:Gold / Q000737:chemistry; D061925:Immobilized Nucleic Acids / Q000737:chemistry; D060106:Lakes / Q000032:analysis; D057230:Limit of Detection; D008163:Luminescent Measurements / Q000379:methods*; D008628:Mercury / Q000032:analysis*; D053768:Metal Nanoparticles / Q000737:chemistry; D015345:Oligonucleotide Probes / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry; D010619:Phenazines / Q000737:chemistry; D013941:Thymine / Q000737:chemistry; D017971:Tin Compounds / Q000737:chemistry; D014867:Water / Q000032:analysis*
chemical_list: D002413:Cations, Divalent; D004277:DNA, Single-Stranded; D061925:Immobilized Nucleic Acids; D015345:Oligonucleotide Probes; D009942:Organometallic Compounds; D010619:Phenazines; D017971:Tin Compounds; D014867:Water; C109984:indium tin oxide; D006046:Gold; C077849:bis(2,2'-bipyridyl)(dipyrido(3,2-alpha-2',3'-c)phenazine)ruthenium (II); D008628:Mercury; D013941:Thymine
keywords: DNA biosensor; Electrochemiluminescence; Hg(2+); [Ru(bpy)(2)(dppz)](BF(4))(2)