Sensors and methods for determination of analytes are provided. Analytes including explosives (e.g., RDX or PETN) may be determined by monitoring, for example, a change in an optical signal of a material upon exposure to the analyte. In some embodiments, the analyte and the material may interact via a chemical reaction to form a new emissive species. Embodiments described herein may provide inexpensive sensors with high selectivity and sensitivity.