A polymer matrix composite comprising a porous polymeric network; and a plurality of indicator particles distributed within the polymeric network structure; wherein the indicator particles are present in a range from 1 to 99 weight percent, based on the total weight of the indicator particles and the polymer (excluding the solvent); and wherein the polymer matrix composite has a density of at least 0.05 g/cm3; and methods for making the same. The polymer matrix composites are useful, for example, as sensors.