DDA was used to study the relationship between the number of beads forming gratings and ratio of first and zeroth order diffraction intensities.

A very flexible modeling program was developed to design complicated objects for DDA.

Material and spatial effects of bead distribution on surfaces were studied.

It has been shown that bead enhanced grating biosensor can be useful for fast detection of small amounts of biomolecules.

Experimental results qualitatively support the simulations and thus open a way to optimize the grating biosensors.