Enzyme-free fluorescent detection of microcystin-LR using hairpin DNA-templated copper nanoclusters as signal indicator.
Talanta
; 202: 279-284, 2019 Sep 01.
Article
em En
| MEDLINE
| ID: mdl-31171183
ABSTRACT
Microcystin-LR (MC-LR) is a potent hepatotoxin that is often associated with blooms of cyanobacteria. The analysis of trace MC-LR plays important role in environmental and health fields. Herein, we developed a low-cost and enzyme-free detection method of MC-LR by using hairpin DNA-templated copper nanoclusters (hpDNA-CuNCs) as fluorescent probe. The hpDNA-template was designed and fabricated by a MC-LR aptamer loop and a double strand stem, which can specifically recognize target MC-LR with strong affinity. The AT-rich and complementary double strand stem serves as a template for the formation of CuNCs. The formed fluorescent sensing probe of hpDNA-CuNCs exhibits maximum emission wavelength at 575â¯nm. Upon the addition of target MC-LR into the hpDNA-CuNCs, we observed fluorescence was quenched considerably due to the high affinity between MC-LR and hpDNA aptamer strand loop, which indicated a conformational change of hairpin probe from the stem-loop DNA structure to single-stranded DNA. Then, the change of fluorescence intensity can be used to monitor the concentration of MC-LR from 0.005 to 1200⯵gâ¯L-1 with a detection limit of 0.003â¯ngâ¯L-1. Compared with the previous reports, this method does not require complex DNA sequence design, fluorescence dye label and sophisticated experimental techniques. Moreover, the target MC-LR in real water samples has been detected.
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Base de dados:
MEDLINE
Assunto principal:
Poluentes Químicos da Água
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DNA
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Técnicas Biossensoriais
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Cobre
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Microcistinas
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Nanopartículas Metálicas
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Fluorescência
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Corantes Fluorescentes
Idioma:
En
Ano de publicação:
2019
Tipo de documento:
Article