Surface plasmon resonance sensors exploit the high sensitivity to local perturbations of plasma waves in a thin metal layer. These devices have a wide range of applications as biomedical, environmental, industrial, and homeland security. We concentrate on the theoretical aspects of the sensing principle. By calculations at various indexes of refraction we proved that using substrate material of higher index, sensitivity and dynamics range improve conspicuously. Finally, we show experimental data taken using a special transparent ceramic material of exceptionally high index of refraction n= 2.04. Tests demonstrate sensitivity about one order of magnitude better than those obtained with conventional BK7 glass. (C) 2008 American Institute of Physics.