Related Experiment Video
Updated: Jun 8, 2026
09:09
A Label-free Technique for the Spatio-temporal Imaging of Single Cell Secretions
Published on: November 23, 2015
Label-free biosensing based on single gold nanostars as plasmonic transducers
Srujan K Dondapati1, Tapan K Sau, Calin Hrelescu
1Photonics and Optoelectronics Group, Physics Department and Center for Nanoscience (CeNS), Ludwig-Maximilians-Universität München, Amalienstrasse 54, 80799 Munich, Germany.
ACS Nano
|October 15, 2010
Summary
Gold nanostars offer highly sensitive, label-free biosensing by detecting spectral shifts in plasmon resonances. This method accurately identifies low concentrations of streptavidin molecules, demonstrating potential for advanced biosensor applications.
Area of Science:
- Nanotechnology
- Biophysics
- Materials Science
Background:
- Gold nanostars exhibit unique optical properties due to their complex morphology.
- Plasmon resonances in gold nanostars are sensitive to their local dielectric environment.
Purpose of the Study:
- To investigate the use of gold nanostars for highly sensitive, label-free biosensing.
- To characterize the spectral shifts in plasmon resonances upon molecular binding.
Main Methods:
- Synthesis and characterization of gold nanostars.
- Utilizing single nanoparticle spectroscopy to monitor plasmon resonance shifts.
- Immobilization of biotin on gold nanostars for streptavidin detection.
Main Results:
- Gold nanostars display multiple plasmon resonances, with lower energy modes being most sensitive.
- Detection of streptavidin molecules via spectral shifts in tip-related plasmon resonances.
- Achieved sensitivity down to 0.1 nM streptavidin with a 2.3 nm spectral shift.
Conclusions:
- Gold nanostars are effective platforms for sensitive, label-free biosensing.
- The spectral sensitivity of nanostar plasmon resonances enables precise molecular detection.
- This approach holds promise for developing advanced biosensor technologies.
