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Hairpin DNA‐Dependent Click Conjugation of Oligonucleotides for Electrochemical Monitoring of Copper(II)
Author(s) -
Tang Dianyong,
Zhang Jin,
Tang Ying,
Teng Liumei,
Xia Biyun,
Tang Dianping
Publication year - 2015
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.201500336
Subject(s) - click chemistry , oligonucleotide , copper , chemistry , methylene blue , azide , combinatorial chemistry , redox , electrochemistry , cycloaddition , methylene , alkyne , catalysis , photochemistry , inorganic chemistry , dna , electrode , organic chemistry , biochemistry , photocatalysis
A new electrochemical sensing platform was designed for sensitive detection of copper(II) (Cu 2+ ) based on click conjugation of two short oligonucleotides by using methylene blue‐functionalized hairpin DNA as the template. The analyte (Cu 2+ ) was in situ reduced to Cu + by sodium ascorbate, which catalyzed the click conjugation between two single‐stranded oligonucleotides one was labelled with a 5′‐alkyne and the other with 3′‐azide group via the Cu + ‐catalyzed azide‐alkyne cycloaddition. The newly formed long‐chain oligonucleotide induced the conformational change of hairpin DNA to open the hairpin, resulting in methylene blue far away from the electrode for the decrease of redox current. Under optimal conditions, the decrease in the electronic signal was directly proportional to target Cu 2+ concentration, and allowed the detection of Cu 2+ at a concentration as low as 1.23 nM. Our strategy also displayed high selectivity for Cu 2+ against other metal ions owing to the highly specific Cu + ‐catalyzed click chemistry reaction, and was applicable for monitoring of Cu 2+ in drinking water with satisfactory results.