A lateral flow device is disclosed. The lateral flow device includes a substrate having a flow path and a detection zone disposed along the flow path. The detection zone includes an immobilized target-binding moiety directed against a target of a Raman-active complex. A portion of the detection zone has a dimension that is less than another dimension of the lateral flow device upflow from the detection zone or a first region of the detection zone has a chemical difference from a second region of the detection zone. Also disclosed are methods of conducting a lateral flow assay and methods of making a lateral flow device.