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Gold Nanoparticle Synthesis
Published on: July 10, 2021
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Extinction Coefficient of Gold Nanostars
Helena de Puig1, Justina O Tam2, Chun-Wan Yen2
1Dept. of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139.
The Journal of Physical Chemistry. C, Nanomaterials and Interfaces
|December 27, 2016
Summary
Gold nanostars (NStars) synthesis in HEPES buffer yields varied sizes and optical properties. Their extinction coefficients correlate with theoretical models, and biomolecule conjugation is demonstrated for biological applications.
Area of Science:
- Nanotechnology
- Biomedical Engineering
- Materials Science
Background:
- Gold nanostars (NStars) possess unique optical properties and surface chemistry, making them promising for biological applications.
- Facile synthesis methods are crucial for tailoring NStar properties for specific uses.
Purpose of the Study:
- To synthesize gold nanostars (NStars) in HEPES buffer with controlled size, shape, and optical properties.
- To experimentally determine the extinction coefficients of synthesized NStars at their surface plasmon resonances (SPR).
- To validate experimental findings with theoretical models and demonstrate biomolecule conjugation.
Main Methods:
- Synthesis of NStars in HEPES buffer at varying HEPES/Au ratios.
- Measurement of extinction coefficients at maximum SPR.
- Theoretical modeling using discrete dipole approximation (DDA) to simulate extinction spectra.
- Conjugation of DNA and antibodies to NStars.
Main Results:
- NStars synthesized with varying sizes and shapes, exhibiting diverse optical properties.
- Measured extinction coefficients ranged from 5.7 × 10^8 to 26.8 × 10^8 M^-1cm^-1.
- Experimental extinction coefficients showed good correlation with DDA theoretical models.
- Successful conjugation of DNA and antibodies to NStars was achieved.
Conclusions:
- HEPES buffer composition influences NStar morphology and optical characteristics.
- The study provides a validated method for characterizing NStar optical properties.
- Demonstrated biomolecule conjugation highlights the potential of these NStars for biosensing and targeted delivery.
