A structure or method for detecting a substance using conductive surfaces. Segments of conductive wire are disposed adjacent each of the surfaces and multi-turn coils are also disposed between the two surfaces, typically such that the windings of the coils are disposed between the respective conductive wires and the surfaces. A linear chirp signal, is applied to the wire segments. With the coils deactivated, emissions from the wire induce the Nuclear Quadrupole Resonance (NQR). With the coils activated to generate a static magnetic field, emissions from the wire induce Nuclear Magnetic Resonance (NMR). As a result, the characteristics of a substance located between the conductive surfaces may be determined using either or both resonant modalties.