Abstract: Among other things, methods and systems are described for detecting chemicals including explosive materials. For example, a system for detecting materials includes a sample gathering unit designed to obtain a portion of a target material to be tested. In addition, the system includes a sample holding unit that has a first end designed to attach to the sample gathering unit and form a housing that retains at least the obtained portion of the target material. Further, a reagent holding unit is included and designed to attach to a second end of the sample holding unit. The reagent holding unit is designed to introduce the reagent into the formed housing to mix with the obtained target material and start a chemical reaction.