We use a gold-nanoparticle coated film to achieve highly spatially resolved biosensing that is based on localized surface-plasmon resonance. Unlike the planar gold film employed for conventional surface-plasmon resonance sensing, the gold-nanoparticle film relies exclusively on shifting of the peak extinction wavelength for detection of biointeraction and does not depend critically on the angle of incidence. These characteristics permit integration of surface-plasmon resonance with large-numerical-aperture optics to achieve biosensing with high sensitivity and spatial resolution as high as 25 μm.
© 2004 Optical Society of America
(170.0170) Medical optics and biotechnology : Medical optics and biotechnology
(170.0180) Medical optics and biotechnology : Microscopy
(240.6680) Optics at surfaces : Surface plasmons
(300.1030) Spectroscopy : Absorption
Xin Hong and Fu-Jen Kao, "Microsurface Plasmon Resonance Biosensing Based on Gold-Nanoparticle Film," Appl. Opt. 43, 2868-2873 (2004)