1. Colorimetric determination of DNA using an aptamer and plasmonic nanoplatform.
- Author
-
Sang F, Yin S, Pan J, Liu D, and Zhang Z
- Subjects
- Aptamers, Nucleotide genetics, DNA chemistry, DNA genetics, Gold chemistry, Inverted Repeat Sequences, Limit of Detection, Mercury chemistry, Nucleic Acid Hybridization, Polyethylenes chemistry, Quaternary Ammonium Compounds chemistry, Thymine chemistry, Aptamers, Nucleotide chemistry, Colorimetry methods, DNA analysis, Metal Nanoparticles chemistry
- Abstract
A facile plasmonic nanoplatform was developed for rapid and sensitive determination of nucleic acid. Hg
2+ -regulated molecular beacon (MB, hairpin) containing rich thymine (T) bases at both ends is used as the probe. A hairpin structure can be formed in the MB probe due to the strong binding of Hg2+ to T. However, in the presence of target DNA, the hairpin structure is opened owing to target DNA-specific hybridization with the aptamer. Simultaneously, the opened MB interacts with poly(diallyldimethylammonium chloride) (PDDA) and hinders PDDA-induced aggregation of AuNPs, accompanied by a color change from blue to red and a decrease in absorption ratio (A620 /A520 ). Hence, a good linear relationship was observed between the decreased absorption ratio (A620 /A520 ) and DNA concentration ranging from 0.02 to 2 nmol/L with a low detection limit of 4.42 pmol/L. Moreover, this nanoplatform has been successfully utilized to discriminate between perfect target and mismatch sequences. More importantly, the bioassay is simple, versatile, rapid, and cost-effective compared with other common methods, which holds great promise for clinical diagnosis and biomedical application. Graphical abstract.- Published
- 2020
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