A concentrator for detecting biological and/or chemical materials in an
environment. The concentrator comprises an engineered superlattice
structure having alternating layers of elemental, binary or ternary group
III-group V, or group IV-group IV semiconducting materials. A method for
detecting biological and/or chemical materials in an environment using
the concentrator. The method comprising exposing the concentrator to the
biological and/or chemical materials in an environment and activating the
superlattice structure optically or electrically followed by the
detection of the biological and/or chemical materials.