Microfluidic paper-based analytical devices for quantification of analytes in interstitial fluid

A manufacture for assaying a first analyte from interstitial fluid, said manufacture comprising needles that draw up said interstitial fluid when inserted through a patient's skin, a paper substrate in fluid communication with said needles to receive said interstitial fluid, said paper substrate comprising a sampling zone that receives said interstitial fluid from said needles, and a detector, wherein said detector has been functionalized to provide a visual indicator in response to exposure to said first analyte and wherein said needles are hydrogel needles.