Nanoarray-Based Biomolecular Detection Using Individual Au Nanoparticles with Minimized Localized Surface Plasmon Resonance Variations

• DOI: 10.1021/ac200432c
• Publication Date: 2011-03-09T13:03:27Z
• Authors: Longhua Guo; Abdul Rahim Ferhan; Kijoon Lee; Dong-Hwan Kim
• Keywords: Base Sequence; Thrombin; Metal Nanoparticles; Nanotechnology; Gold; 02 engineering and technology; Aptamers, Nucleotide; Surface Plasmon Resonance; 0210 nano-technology

Here, we present a mean to expand the use of individual metallic nanoparticles to two-dimensional plasmonic nanoarrays. An optical detection platform to track down localized surface plasmon resonance (LSPR) signals of individual nanoparticles on substrates was built for the application of plasmonic nanoarrays. A pseudoimage of nanoparticles on a substrate was reconstructed from their scattering spectra obtained by scanning a user-defined area. The spectral and spatial resolutions of the system were also discussed in detail. Most importantly, we present a method to normalize the localized surface plasmon resonance from geometrically different nanoparticles. After normalization, plasmonic responses from different particles become highly consistent, creating well-fitted dose-response curves of both surrounding refractive index changes and receptor-analyte binding to the surface of individual nanoparticles. Finally, the proof-of-concept system for plasmonic nanoarray detection is demonstrated by the measurement of the aptamer-thrombin binding event.