The fundamental and applied engineering issues to develop stable and functional bioactive papers for health and environmental diagnostics are investigated. Enzymes are directly physisorbed on paper or retained on paper with a polymer. The reactivity and the thermal stability of enzymatic papers are quantified using an advanced colorimetric technique. Paper bioassays to identify antigens and antibodies in a biofluid, such as blood, are investigated. The blood typing using a low cost paper diagnostic is shown. The feasibility of thermal ink jet printing is illustrated for the...