Electrochemiluminescence sensor using quantum dots based on a G-quadruplex aptamer for the detection of Pb2+

A layer of aptamer probes with hairpin structures was modified on the surface of Fe3O4–Au magnetic nanoparticles (Fe3O4–Au-Aptamer). The “stem-loop” structure of the hairpin aptamer was opened when adding Pb2+. Then a G-quadruplex was formed, exposing 3′-NH2, which bound to CdTe quantum dots. Thus the magnetic nanoparticles were separated and enriched on the surface of the magnetic controlled gold electrode (MCGE). By this method, a “turn-on” electrochemiluminescence (ECL) sensor for Pb2+ detection using quantum dots was constructed. The changes to the structure of the aptamer were characterized by cyclic voltammetry, AC impedance measurements, transmission electron microscopy and UV-Vis absorption spectroscopy. Pb2+ concentration and ECL signal presented a linear relationship in the range 2.0 × 10−10–1.0 × 10−8 M. The detection limit was 1.08 × 10−11 M. In addition, the biosensor showed good selectivity, stability and reproducibility.

[1]  H. Ju,et al.  Low-potential electrochemiluminescent sensing based on surface unpassivation of CdTe quantum dots and competition of analyte cation to stabilizer. , 2010, Analytical chemistry.

[2]  Feng Li,et al.  Crystal violet as a G-quadruplex-selective probe for sensitive amperometric sensing of lead. , 2011, Chemical communications.

[3]  Itamar Willner,et al.  DNAzymes for sensing, nanobiotechnology and logic gate applications. , 2008, Chemical Society reviews.

[4]  Jaebeom Lee,et al.  Ultrasensitive DNA monitoring by Au–Fe3O4 nanocomplex , 2012 .

[5]  Jiming Hu,et al.  A sensitive and selective label-free DNAzyme-based sensor for lead ions by using a conjugated polymer , 2012 .

[6]  Chunhai Fan,et al.  Aptamer-based biosensors , 2008 .

[7]  Deming Kong,et al.  Ag+ and cysteine quantitation based on G-quadruplex-hemin DNAzymes disruption by Ag+. , 2010, Analytical chemistry.

[8]  S. Dong,et al.  Quantum Dot Electrochemiluminescence in Aqueous Solution at Lower Potential and Its Sensing Application , 2008 .

[9]  Yi Lu,et al.  Metal ion-dependent DNAzymes and their applications as biosensors. , 2012, Metal ions in life sciences.

[10]  Z. Deng,et al.  Colorimetric Hg2+ detection with a label-free and fully DNA-structured sensor assembly incorporating G-quadruplex halves. , 2009, The Analyst.

[11]  Y. Chai,et al.  Target recycling amplification for sensitive and label-free impedimetric genosensing based on hairpin DNA and graphene/Au nanocomposites. , 2011, Chemical communications.

[12]  Zhenzhen Lin,et al.  Impedimetric immobilized DNA-based sensor for simultaneous detection of Pb2+, Ag+, and Hg2+. , 2011, Analytical chemistry.

[13]  Ciara K O'Sullivan,et al.  Aptamer conformational switch as sensitive electrochemical biosensor for potassium ion recognition. , 2006, Chemical communications.

[14]  Shaojun Dong,et al.  Sensitive and Selective Determination of Cu2+ by Electrochemiluminescence of CdTe Quantum Dots , 2008 .

[15]  Zhenzhen Lin,et al.  Pb2+ induced DNA conformational switch from hairpin to G-quadruplex: electrochemical detection of Pb2+. , 2011, The Analyst.

[16]  Yi Lu,et al.  Metal ion sensors based on DNAzymes and related DNA molecules. , 2011, Annual review of analytical chemistry.

[17]  Jeffery T. Davis,et al.  Pb EXAFS studies on DNA quadruplexes: identification of metal ion binding site. , 2002, Biochemistry.

[18]  J. Grasby,et al.  Sequence-specific cleavage of RNA in the absence of divalent metal ions by a DNAzyme incorporating imidazolyl and amino functionalities. , 2004, Nucleic acids research.

[19]  Zhenyu Lin,et al.  A sensitive and specific electrochemiluminescent sensor for lead based on DNAzyme. , 2009, Chemical communications.

[20]  S. Jayasena.  Aptamers: an emerging class of molecules that rival antibodies in diagnostics. , 1999, Clinical chemistry.

[21]  H. Luo,et al.  A label-free thrombin binding aptamer as a probe for highly sensitive and selective detection of lead(II) ions by a resonance Rayleigh scattering method. , 2012, The Analyst.

[22]  S. Balasubramanian,et al.  Quantitative visualization of DNA G-quadruplex structures in human cells. , 2013, Nature chemistry.

[23]  R. Shafer,et al.  Lead is unusually effective in sequence-specific folding of DNA. , 2000, Journal of molecular biology.

[24]  Tao Li,et al.  Potassium-lead-switched G-quadruplexes: a new class of DNA logic gates. , 2009, Journal of the American Chemical Society.

[25]  R. Shafer,et al.  Characterization of an unusual folding pattern in a catalytically active guanine quadruplex structure , 2006, Biopolymers.

[26]  Xiaogang Peng,et al.  Experimental Determination of the Extinction Coefficient of CdTe, CdSe, and CdS Nanocrystals , 2003 .

[27]  Heyou Han,et al.  Electrogenerated chemiluminescence from thiol-capped CdTe quantum dots and its sensing application in aqueous solution. , 2007, Analytica chimica acta.

[28]  D. Patel,et al.  Adaptive recognition by nucleic acid aptamers. , 2000, Science.

[29]  Nikolai Gaponik,et al.  Application of polymer quantum dot-enzyme hybrids in the biosensor development and test paper fabrication. , 2012, Analytical chemistry.

[30]  Mingwu Shen,et al.  Facile assembly of Fe3O4@Au nanocomposite particles for dual mode magnetic resonance and computed tomography imaging applications , 2012 .

[31]  Guonan Chen,et al.  A G-quadruplex based label-free fluorescent biosensor for lead ion. , 2012, Biosensors & bioelectronics.

[32]  L. Gold,et al.  Systematic evolution of ligands by exponential enrichment: RNA ligands to bacteriophage T4 DNA polymerase. , 1990, Science.

[33]  J. Szostak,et al.  Selection in vitro of single-stranded DNA molecules that fold into specific ligand-binding structures , 1992, Nature.