A colorimetric sensor for detecting an analyte of interest in a fluid sample includes a lamellar photonic material having alternating layers of a first polymer layer and a second polymer layer. Each first polymer layer can be a molecularly imprinted polymer defining a cavity shaped to receive an analyte of interest. The photonic material is configured such that, when an analyte contacts the photonic material and becomes disposed within a cavity of the molecularly imprinted polymer, a refractive property of the photonic material changes, causing a detectable color change in the sensor.