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A fluorescent DNAzyme-based biosensor for the detection of lead ions using carbon quantum dots prepared from grapefruit peel.
- Source :
-
New Journal of Chemistry . 3/14/2024, Vol. 48 Issue 10, p4253-4261. 9p. - Publication Year :
- 2024
-
Abstract
- As a type of heavy metal ion, lead ions can pollute the environment and endanger human health, and thus, research on the detection of lead ions is crucial. In this study, a simple fluorescent biosensor based on lead ion-DNAzyme (Pb-enzyme) cleavage and a hemin/carbon quantum dot complex for the detection of lead ions was fabricated. Magnetic beads were linked to a substrate chain modified by adenosine ribonucleotide (Pb-substrate) via avidin-biotin interaction, Pb-enzyme bound Pb-substrate, and multifunctional magnetic beads were prepared. Carbon quantum dots were prepared from grapefruit peel (G-CQDs) and were characterized using transmission electron microscopy, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, ultraviolet and visible absorption spectroscopy, and fluorescence spectroscopy analyses. The results indicated that the average particle size of G-CQDs was 2.41 nm, and G-CQDs emitted a bright blue color under ultraviolet irradiation at a wavelength of 350 nm. However, the fluorescence of G-CQDs could be quenched by hemin. When a G-quadruplex was combined with hemin, the fluorescence of hemin/G-CQDs was recovered. In the presence of lead ions, the cleavage activity of the Pb-enzyme was induced, the Pb-substrate strand was cleaved at the modification site, and a single-stranded DNA was released. The single-stranded DNA bound to a hairpin probe, and G-rich sequences of the hairpin probe formed a G-quadruplex, which could restore the fluorescence of hemin/G-CQDs. This fluorescent biosensor exhibits excellent selectivity and sensitivity, with a limit of detection (LOD) value of 5 nM, for lead ions. Moreover, the fluorescent biosensor can be further used to test water samples. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 11440546
- Volume :
- 48
- Issue :
- 10
- Database :
- Academic Search Index
- Journal :
- New Journal of Chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 175824567
- Full Text :
- https://doi.org/10.1039/d3nj05829h