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A "Turn-On" Fluorescence Copper Biosensor Based on DNA Cleavage-Dependent Graphene Oxide-dsDNA-CdTe Quantum Dots
Liyun Ding1, Bing Xu2, Tao Li3
1National Engineering Laboratory for Fiber Optic Sensing Technology, Wuhan University of Technology, Wuhan 430070, China. dlyw@whut.edu.cn.
Sensors (Basel, Switzerland)
|August 12, 2018
Summary
A new fluorescent biosensor detects copper ions. This graphene oxide-DNA-quantum dot complex shows "turn-on" fluorescence when copper is present, offering selective detection.
Area of Science:
- * Materials Science
- * Analytical Chemistry
- * Biotechnology
Background:
- * Development of sensitive and selective methods for metal ion detection is crucial in environmental and biological monitoring.
- * Graphene oxide (GO) and semiconductor quantum dots (QDs) offer unique optical and electronic properties for biosensing applications.
- * Fluorescence resonance energy transfer (FRET) is a powerful tool for designing quenching-based biosensors.
Purpose of the Study:
- * To develop a novel
- turn-on
- fluorescent copper biosensor.
- * To investigate the sensing mechanism based on graphene oxide, DNA, and CdTe quantum dots.
- * To evaluate the sensor's selectivity and sensitivity towards copper ions.
Main Methods:
- * Fabrication of a graphene oxide-dsDNA-CdTe quantum dots complex using a chemical crosslinking method.
- * Characterization of the complex's optical and structural properties using fluorescence spectroscopy and transmission electron microscopy.
- * Investigation of the fluorescence response mechanism in the presence of copper ions, including DNA cleavage and G-quadruplex formation.
Main Results:
- * The developed GO-dsDNA-CdTe QDs complex exhibited fluorescence quenching due to FRET between GO and CdTe QDs.
- * Copper ions triggered DNA cleavage, leading to G-quadruplex formation and subsequent separation of QDs from GO, restoring fluorescence.
- * The sensor demonstrated a concentration-dependent
- turn-on
- fluorescence response to copper ions with good linearity and high selectivity over other metal ions.
Conclusions:
- * A novel and effective
- turn-on
- fluorescent copper biosensor was successfully developed.
- * The sensing mechanism relies on copper-induced DNA cleavage and subsequent G-quadruplex formation, leading to fluorescence recovery.
- * The proposed biosensor shows significant potential for sensitive and selective detection of copper ions in various applications.
