We report the use of plasmonic responses of single gold nanoparticles (AuNPs) with various sizes for the analysis of biomolecular recognition. We also describe the relationship between particle size and plasmonic response induced by the binding of receptors and target analytes. To investigate the plasmonic response of AuNPs, Rayleigh light scattering spectra were collected from individual AuNPs using a dark-field microspectroscopy system. Using prostate-specific antigen (PSA) as a model, the linear dynamic range was obtained in the concentration range of 10-4 to 10 ng/ml, with the smallest detectable concentration at 0.1 pg/ml corresponding to localized surface plasmon resonance (LSPR) λmax shifts of approximately 2.95 nm. This result indicates that individual AuNPs can be used for development of a very sensitive, robust, simple, and label-free biosensor to detect protein biomarkers. Furthermore, the method possesses great potential for monitoring other biological interactions.
Bibliographical noteFunding Information:
This work was supported by the Korea Science and Engineering Foundation (KOSEF) National Research Laboratory (NRL) Program ( R0A-2008-000-20078-0 ), the Basic Science Research Program ( 2010-0027771 ), and a grant from the Carbon Dioxide Reduction & Sequestration Research Center ( DG2-201 ), one of the 21st Century Frontier Programs funded by the Ministry of Science and Technology of the Korean government of the Republic of Korea .
- Biomolecular recognition
- Gold nanoparticle (AuNP)
- Localized surface plasmon resonance (LSPR)
- Resonant Rayleigh light scattering
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology