Use of Holographic Sensors

A method of measuring the amount of an analyte in a sample, comprises (a) passing the sample through a flow channel in or on a holographic sensor, wherein the analyte interacts with and is retained by the sensor and wherein the interaction of the analyte changes an optical property of the sensor, and (b) monitoring analyte interaction, wherein the distance along the flow channel at which analyte interaction occurs or the area of the channel over which analyte interaction occurs, indicates the amount of analyte in the sample. Further, a method of detecting an analyte in a sample, comprises (a) passing the sample through a flow channel in or on a holographic sensor, wherein the analyte interacts with the sensor, thereby changing an optical property of the sensor, and wherein the flow channel defines a symbol; and (b) detecting the analyte by observing the appearance, disappearance or change in appearance of the symbol.