Journal
SENSORS AND ACTUATORS B-CHEMICAL
Volume 254, Issue -, Pages 206-213Publisher
ELSEVIER SCIENCE SA
DOI: 10.1016/j.snb.2017.07.021
Keywords
Ratiometric fluorescence sensor; Quantum dots; Magnetic beads; Bacillus thuringiensis transgene; Fluorescence resonance energy transfer
Funding
- National Key R D Program [2016YFD0500700]
- National Natural Science Foundation of China [21375043, 21175051]
- Sci-tech Innovation Foundation of Huazhong Agriculture University [2662017PY042]
Ask authors/readers for more resources
Improving the accuracy and sensitivity of fluorescence analysis is of great importance in clinical diagnosis, environmental and food monitoring. Herein, based on fluorescence resonance energy transfer (FRET), a facile and effective ratiometric fluorescence sensor was constructed for the detection of Bacillus thuringiensis (Bt) special gene fragment. In this work, green quantum dots (gQDs) decorated Fe3O4 magnetic beads (MBs) with streptavidin (SA) were acted as donor, and gold nanoparticles (GN) modified red quantum dots (rQDs@SiO2) with hairpin DNA as receptor. When the target sequences exist, the hairpin DNA were unfolded and subsequently captured by MBs@SiO2@gQD-SA via biotin-SA specific interaction. By using the magnetic separation method, the hybridized composites could be easily purified for florescence tests. By this means, rQDs@SiO2@GN could enhance the fluorescence intensity of rQDs (I-620) and simultaneously quench the fluorescence response of gQDs (I-540) via FRET. Under optimal conditions, the ratio of fluorescence intensity at 620 nm and 540 nm (I-620/I-540) showed that Bt transgene fragment detection owning a good linearity from 5.0 pM to 10 nM with a detection limit of 0.10 pM (SIN = 3). The high selectivity of the probes was also demonstrated using the single-base and three-base mismatch method. (C) 2017 Elsevier B.V. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available