Detection of virus-like nanoparticles via scattering using a chip-scale optical biosensor

A local evanescent array coupled biosensor is used to detect spherical polystyrene nanoparticles with diameters of 40 nm and 200 nm, whose sizes and refractive index are similar to virus particles. The sensitivity is similar to 1%/particle for 200 nm particles and 0.04%/particle for 40 nm particles. Mie scattering in an evanescent field theory is used to model the scattered light intensity for both sizes of nanoparticles. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4758294]