Eurekalert October 11, 2019
Researchers at the University of New Mexico studied arrays composed of silver nanoparticles placed in a repeating pattern. When the arrays are illuminated with light, each of the particles produces a strong response, which, in turn, results in enormous collective behaviors if all the particles can interact with one another. This happens at certain wavelengths of incident light, which are determined by the interparticle spacing of the array, and can result in electric fields that are thousands, or even tens of thousands, of times that of the light shined on the array. The strength of this field enhancement depends on the geometrical properties of the array, such as the spacing between the nanospheres and the size of the spheres themselves. They found that decreasing the density of nanoparticles in the array produces field enhancements that are not only larger but extend farther away from the array. The near-field enhancements could be a game changer for technologies like ultrasensitive biosensing. The system has applications ranging from vivid, high-resolution color printing to biosensing…read more. Open Access TECHNICAL ARTICLE
Artistic depiction of the system under study. As the size of the particles is reduced, the field enhancement increases. Credit: University of New Mexico Department of Physics