A device qualitatively and quantitatively detects blood analytes such as alcohol by passing sweat through a semi-permeable membrane to a reaction chamber. In the reaction chamber, the sweat can react with reagents that produce a color when reacted with the analyte. The presence of the color is used to determine that the analyte is present. The intensity of the color change can be measured to quantify the amount of analyte. The device can include tamper resistance elements to prevent the device from being removed.
