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Multicolor Fluorescence Detection for Droplet Microfluidics Using Optical Fibers
Published on: May 5, 2016
A reversible dual-response fluorescence switch for the detection of multiple analytes
Junlong Geng1, Ping Liu, Bianhua Liu
1Institute of Intelligent Machines, Chinese Academy of Sciences, PO Box 1130, Hefei, Anhui 230031, China.
Chemistry (Weinheim an Der Bergstrasse, Germany)
|February 13, 2010
Summary
This study presents reusable silica nanoparticles that act as a dual fluorescence sensor. They detect proton targets and 2,4,6-trinitrotoluene (TNT) with opposite fluorescence changes, enabling sensitive detection.
Area of Science:
- Nanomaterials Science
- Analytical Chemistry
- Chemical Sensing
Background:
- Developing selective and sensitive detection methods for analytes like proton targets and 2,4,6-trinitrotoluene (TNT) is crucial.
- Fluorescence-based sensing offers high sensitivity and selectivity, but often requires specific probes for each target.
- Silica nanoparticles provide a versatile platform for developing advanced sensing materials due to their tunable properties and large surface area.
Purpose of the Study:
- To develop a reversible dual fluorescence switch for simultaneous detection of proton targets and TNT.
- To utilize silica nanoparticles functionalized with a nitrobenzoxadiazole (NBD) fluorophore and an organic amine.
- To investigate the opposite fluorescence response mechanisms for proton and TNT detection.
Main Methods:
- Synthesized fluorescent silica nanoparticles by surface modification with NBD fluorophore and organic amine.
- Investigated fluorescence responses to protonation and TNT binding, analyzing mechanisms of photoinduced electron transfer (PET) and fluorescence resonance energy transfer (FRET).
- Assembled functionalized nanoparticles onto etched silicon wafers to create a sensing chip for practical applications.
Main Results:
- Achieved opposite fluorescence responses: enhancement for proton targets (PET inhibition) and quenching for TNT (FRET).
- Demonstrated reversibility of the fluorescence signal through washing, allowing for nanoparticle reuse.
- Successfully assembled nanoparticles into a chip for detecting herbicide and TNT residues in small sample volumes (10 microL).
Conclusions:
- The NBD-grafted silica nanoparticles offer a robust platform for dual-analyte detection with reversible signals.
- The developed sensing chip provides a convenient and flexible method for multianalyte detection.
- This approach holds promise for developing portable and reusable sensors for environmental and security applications.
