title: Wide-field single metal nanoparticle spectroscopy for high throughput localized surface plasmon resonance sensing.
abstract: Noble metal nanoparticles (mNPs) have a distinct extinction spectrum arising from their ability to support Localized Surface Plasmon Resonance (LSPR). Single-particle biosensing with LSPR is label free and offers a number of advantages, including single molecular sensitivity, multiplex detection, and in vivo quantification of chemical species etc. In this article, we introduce Single-particle LSPR Imaging (SLI), a wide-field spectral imaging method for high throughput LSPR biosensing. The SLI utilizes a transmission grating to generate the diffraction spectra from multiple mNPs, which are captured using a Charge Coupled Device (CCD). With the SLI, we are able to simultaneously image and track the spectral changes of up to 50 mNPs in a single (∼1 s) exposure and yet still retain a reasonable spectral resolution for biosensing. Using the SLI, we could observe spectral shift under different local refractive index environments and demonstrate biosensing using biotin-streptavidin as a model system. To the best of our knowledge, this is the first time a transmission grating based spectral imaging approach has been used for mNPs LSPR sensing. The higher throughput LSPR sensing, offered by SLI, opens up a new possibility of performing label-free, single-molecule experiments in a high-throughput manner.
authors.affiliation: Institute of Materials Research and Engineering, A*STAR, Singapore.
authors.forename: Kok Hao
authors.initials: KH
authors.lastname: Chen
authors.forename: Jonathan
authors.initials: J
authors.lastname: Hobley
authors.forename: Yong Lim
authors.initials: YL
authors.lastname: Foo
authors.forename: Xiaodi
authors.initials: X
authors.lastname: Su
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods*; D001710:Biotin / Q000737:chemistry; D004867:Equipment Design; D053768:Metal Nanoparticles / Q000737:chemistry*; D012680:Sensitivity and Specificity; D012834:Silver / Q000737:chemistry*; D013057:Spectrum Analysis / Q000379:methods; D019809:Streptavidin / Q000737:chemistry; D020349:Surface Plasmon Resonance / Q000295:instrumentation* / Q000379:methods*; D013499:Surface Properties
chemical_list: D012834:Silver; D001710:Biotin; D019809:Streptavidin