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Photoswitchable oligonucleotide-modified gold nanoparticles: controlling hybridization stringency with photon dose
Yunqi Yan1, Jennifer I L Chen, David S Ginger
1Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, USA.
Nano Letters
|April 13, 2012
Summary
New DNA-functionalized gold nanoparticles respond to light. UV light dissociates assemblies, while blue light reassembles them, enabling light-controlled DNA hybridization and single-base mismatch detection.
Area of Science:
- Nanotechnology
- Biotechnology
- Materials Science
Background:
- Oligonucleotide-modified nanoparticles are used for directed assembly and sensing.
- Azobenzene molecules can undergo reversible photoisomerization, changing their shape upon light exposure.
Purpose of the Study:
- To develop novel stimulus-responsive DNA-functionalized gold nanoparticles.
- To investigate the reversible photoswitching of nanoparticle assembly behavior.
- To explore light-based control of DNA hybridization and mismatch detection.
Main Methods:
- Synthesized DNA-functionalized gold nanoparticles incorporating azobenzene-modified oligonucleotides.
- Exposed nanoparticle assemblies to UV and blue light to induce and reverse photoswitching.
- Analyzed the photoinduced melting properties of perfectly complementary and partially mismatched DNA strands.
Main Results:
- Demonstrated reversible photoswitching of nanoparticle assembly behavior triggered by UV and blue light.
- Showed that UV light induces azobenzene trans-cis isomerization, destabilizing DNA duplexes and causing dissociation.
- Confirmed that blue light reverses the isomerization, leading to DNA rehybridization and reassembly.
- Established that photon dose can control DNA hybridization stringency, enabling discrimination of single-base mismatches.
Conclusions:
- Developed a new class of light-responsive DNA-gold nanoparticle systems.
- Validated the use of light as a stimulus to control nanoparticle assembly and disassembly.
- Highlighted the potential for precise control over DNA hybridization and sequence-specific recognition using light.
