title: A signal-on electrogenerated chemiluminescent biosensor for lead ion based on DNAzyme.
abstract: A highly reproducible and sensitive signal-on electrogenerated chemiluminescence (ECL) biosensor based on the DNAzyme for the determination of lead ion was developed. The ECL biosensor was fabricated by covalently coupling 5'-amino-DNAzyme-tagged with ruthenium bis (2,2'-bipyridine) (2,2'-bipyridine-4,4'-dicarboxylic acid)-ethylenediamine (Ru1-17E') onto the surface of graphite electrode modified with 4-aminobenzoic acid, and then a DNA substrate with a ribonucleotide adenosine hybridized with Ru1-17E' on the electrode. Upon binding of Pb(2+) to the Ru1-17E' to form a complex which catalyzed the cleavage of the DNA substrate, the double-stranded DNA was dissociated and thus led to a high ECL signal. The signal linearly increases with the concentration of Pb(2+) in the range from 5.0 to 80 pM with a detection limit of 1.4 pM and a relative standard derivation of 2.3%. This work demonstrates that using DNAzyme tagged with ruthenium complex as an ECL probe and covalently coupling method for the fabrication of the ECL biosensor with high sensitivity, good stability and significant regeneration ability is promising approach.
authors.affiliation: Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Materials Science, Shaanxi Normal University, Xi'an 710062, PR China.
authors.forename: Fen
authors.initials: F
authors.lastname: Ma
authors.forename: Bo
authors.initials: B
authors.lastname: Sun
authors.forename: Honglan
authors.initials: H
authors.lastname: Qi
authors.forename: Hongge
authors.initials: H
authors.lastname: Zhang
authors.forename: Qiang
authors.initials: Q
authors.lastname: Gao
authors.forename: Chengxiao
authors.initials: C
authors.lastname: Zhang
mesh_terms: D010129:4-Aminobenzoic Acid / Q000737:chemistry; D000241:Adenosine / Q000737:chemistry; D015374:Biosensing Techniques / Q000379:methods*; D056831:Coordination Complexes / Q000737:chemistry; D021881:DNA, Catalytic / Q000737:chemistry*; D004566:Electrodes; D006108:Graphite / Q000737:chemistry; D007477:Ions / Q000032:analysis; D007854:Lead / Q000032:analysis*; D008163:Luminescent Measurements / Q000379:methods*; D012428:Ruthenium / Q000737:chemistry
chemical_list: D056831:Coordination Complexes; D021881:DNA, Catalytic; D007477:Ions; D007854:Lead; D006108:Graphite; D012428:Ruthenium; D000241:Adenosine; D010129:4-Aminobenzoic Acid