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Published on: November 10, 2017
High-Sensitivity Sensing of Divalent Copper Ions at the Single Upconversion Nanoparticle Level
Xindong Wang1, Xiaorong Zhang1, Dingxin Huang1
1MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering & Key Laboratory of Micro-Systems and Micro-Structures, Ministry of Education, Harbin Institute of Technology, Harbin 150001, People's Republic of China.
This study presents a novel nanosensor for highly sensitive detection of copper ions (Cu2+) at the single nanoparticle level. The innovative approach achieves superior signal-to-noise ratios and a lower detection limit compared to traditional methods.
Area of Science:
- Nanotechnology
- Analytical Chemistry
- Biomedical Sensing
Background:
- Single-nanoparticle sensing offers high resolution but faces challenges distinguishing faint signals from background noise.
- Existing methods for detecting divalent copper (Cu2+) ions often lack the sensitivity required for precise environmental or biological monitoring.
Purpose of the Study:
- To develop a high-sensitivity nanosensor for detecting Cu2+ ions at the single-nanoparticle level.
- To overcome the limitations of low signal-to-noise ratios in nanoparticle-based sensing applications.
Main Methods:
- Utilized ytterbium- and erbium-doped sodium yttrium fluoride upconversion nanoparticles (UCNPs) as energy donors.
- Functionalized UCNPs with Cu2+-dependent DNAzymes labeled with Black Hole Quencher 1 (BHQ1) dye as energy acceptors.
- Detected Cu2+ by monitoring the cleavage of BHQ1-containing DNAzymes, which triggers upconversion luminescence.
Main Results:
- Achieved single-nanoparticle-level detection of Cu2+ with signal-to-noise ratios exceeding 277 across three orders of magnitude of concentration (sub-nM to μM).
- Established a limit of detection of 220 pM for Cu2+, which is sevenfold lower than ensemble-level detection.
- Observed and characterized stochastic particle-to-particle sensing behavior at the single-nanoparticle level.
Conclusions:
- The developed UCNP-based nanosensor enables highly sensitive single-nanoparticle-level detection of Cu2+ ions.
- This approach significantly enhances signal-to-noise ratios and lowers detection limits for nanoparticle-based biosensing.
- Demonstrated the potential of UCNPs for advanced single-nanoparticle-level biosensing applications.
