Centrifugal microfluidic devices using low-volume reagent storage and inward fluid displacement for presumptive drug detection

•Simple liquid reagent storage method using custom capillary ampule fabrication technique.•Low-volume reagent storage amenable for concentrated acids and volatile reagents.•Performed colorimetric detection of methamphetamine, codeine, heroin, cocaine, MDMA and MDA.•Evaluated the ability to move fluid inward toward the device center of rotation with CO2 formation using sulfuric acid stored in capillary ampules.