Colorimetric detection of mercury ion (Hg2+) based on DNA oligonucleotides and unmodified gold nanoparticles sensing system with a tunable detection range.

Here, we report a simple and sensitive colorimetric detection method for Hg(2+) ions with a tunable detection range based on DNA oligonucleotides and unmodified gold nanoparticles (DNA/AuNPs) sensing system. Complementary DNA strands with T-T mismatches could effectively protect AuNPs from salt-induced aggregation. While in the presence of Hg(2+) ions T-Hg(2+)-T coordination chemistry leads to the formation of DNA duplexes, and AuNPs are less well protected thus aggregate at the same salt concentration, accompanying by color change from red to blue. By rationally varying the number of T-T mismatches in DNA oligonucleotides, the detection range could be tuned. Employing duplex oligonucleotides with 4 T-T mismatches in the sensing system, a sensitive linear range for Hg(2+) ions from 0 to 5 microM and a detection limit of 0.5 microM are obtained. Adding the number of T-T mismatches to 6 and 8, the assay region is enlarged and linear range is tuned. A low proportion of T-T mismatches makes the detection range narrow but the sensitivity high while a high proportion influences the detection limit but enlarges assay region. Besides, the sensor also shows a good selectivity for Hg(2+).

[1]  Xiaofang Hu,et al.  Unmodified gold nanoparticles as a colorimetric probe for potassium DNA aptamers. , 2006, Chemical communications.

[2]  Zusing Yang,et al.  Synthesis of highly fluorescent gold nanoparticles for sensing mercury(II). , 2007, Angewandte Chemie.

[3]  Yi Lu,et al.  Label‐Free Colorimetric Detection of Lead Ions with a Nanomolar Detection Limit and Tunable Dynamic Range by using Gold Nanoparticles and DNAzyme , 2008 .

[4]  Xiaogang Liu,et al.  One-step, room temperature, colorimetric detection of mercury (Hg2+) using DNA/nanoparticle conjugates. , 2008, Journal of the American Chemical Society.

[5]  Jerry R. Miller,et al.  Dispersal of mercury-contaminated sediments by geomorphic processes, sixmile canyon, Nevada, USA: Implications to site characterization and remediation of fluvial environments , 1996 .

[6]  Takashi Fujimoto,et al.  MercuryII-mediated formation of thymine-HgII-thymine base pairs in DNA duplexes. , 2006, Journal of the American Chemical Society.

[7]  Chad A Mirkin,et al.  Colorimetric detection of mercuric ion (Hg2+) in aqueous media using DNA-functionalized gold nanoparticles. , 2007, Angewandte Chemie.

[8]  E. Wang,et al.  Simple and sensitive aptamer-based colorimetric sensing of protein using unmodified gold nanoparticle probes. , 2007, Chemical communications.

[9]  Juewen Liu,et al.  Fast colorimetric sensing of adenosine and cocaine based on a general sensor design involving aptamers and nanoparticles. , 2005, Angewandte Chemie.

[10]  Laszlo Magos,et al.  The toxicology of mercury--current exposures and clinical manifestations. , 2003, The New England journal of medicine.

[11]  Chunhai Fan,et al.  Visual cocaine detection with gold nanoparticles and rationally engineered aptamer structures. , 2008, Small.

[12]  S. Katz,et al.  The reversible reaction of Hg (II) and double-stranded polynucleotides. A step-function theory and its significance. , 1963, Biochimica et biophysica acta.

[13]  Chih-Ching Huang,et al.  Colorimetric determination of urinary adenosine using aptamer-modified gold nanoparticles. , 2008, Biosensors & bioelectronics.

[14]  X. Liu,et al.  A Gold Nanoparticle‐Based Aptamer Target Binding Readout for ATP Assay , 2007 .

[15]  Yi Lu,et al.  A colorimetric lead biosensor using DNAzyme-directed assembly of gold nanoparticles. , 2003, Journal of the American Chemical Society.

[16]  G. B. Brown,et al.  Pyrimidine Nucleosides. I. A New Route for the Synthesis of Thymine Nucleosides1 , 1956 .

[17]  Chad A. Mirkin,et al.  One-Pot Colorimetric Differentiation of Polynucleotides with Single Base Imperfections Using Gold Nanoparticle Probes , 1998 .

[18]  Archana Sharma,et al.  Mercury toxicity in plants , 2000, The Botanical Review.

[19]  Jing Li,et al.  DNAzyme-based colorimetric sensing of lead (Pb2+) using unmodified gold nanoparticle probes , 2008, Nanotechnology.

[20]  Chih-Ching Huang,et al.  Detection of mercury(II) based on Hg2+ -DNA complexes inducing the aggregation of gold nanoparticles. , 2008, Chemical communications.

[21]  Itamar Willner,et al.  Optical analysis of Hg2+ ions by oligonucleotide-gold-nanoparticle hybrids and DNA-based machines. , 2008, Angewandte Chemie.

[22]  Chunhai Fan,et al.  Design of a gold nanoprobe for rapid and portable mercury detection with the naked eye. , 2008, Chemical communications.

[23]  R. G. Freeman,et al.  Preparation and Characterization of Au Colloid Monolayers , 1995 .

[24]  Yi Lu,et al.  Highly sensitive and selective colorimetric sensors for uranyl (UO2(2+)): development and comparison of labeled and label-free DNAzyme-gold nanoparticle systems. , 2008, Journal of the American Chemical Society.

[25]  Yi Lu,et al.  Adenosine-dependent assembly of aptazyme-functionalized gold nanoparticles and its application as a colorimetric biosensor. , 2004, Analytical chemistry.

[26]  Ronghua Yang,et al.  Gold nanoparticle-based colorimetric and "turn-on" fluorescent probe for mercury(II) ions in aqueous solution. , 2008, Analytical chemistry.

[27]  Chojiro Kojima,et al.  15N-15N J-coupling across Hg(II): direct observation of Hg(II)-mediated T-T base pairs in a DNA duplex. , 2007, Journal of the American Chemical Society.

[28]  R. Hickey,et al.  Mercuric ion inhibits the activity and fidelity of the human cell DNA synthesome. , 1997, Toxicology and applied pharmacology.

[29]  Huixiang Li,et al.  Colorimetric detection of DNA sequences based on electrostatic interactions with unmodified gold nanoparticles. , 2004, Proceedings of the National Academy of Sciences of the United States of America.

[30]  Mizuo Maeda,et al.  Rapid aggregation of gold nanoparticles induced by non-cross-linking DNA hybridization. , 2003, Journal of the American Chemical Society.

[31]  Huixiang Li,et al.  Label-free colorimetric detection of specific sequences in genomic DNA amplified by the polymerase chain reaction. , 2004, Journal of the American Chemical Society.