The detection of pesticides or nerve agents has been traditionally carried out in laboratory settings with large and expensive instruments such as gas chromatography coupled with mass spectroscopy (GC-MS) [2], spray mass spectroscopy [3], or high performance liquid chromatography (HPLC) [4]. Recent research efforts focused on developing biosensors platforms that can be incorporated into mobile detection devices. In that respect, paper attracts considerable attention as a matrix for developing low-cost analytical devices [5]. Paper is affordable, abundant, disposable, and has high volume to surface ratio. Paper-based biosensors are usually fast-responding and low-cost diagnostic tools in health and environmental applications. Bioactive papers are obtained by modification of paper matrix with biomolecules in order to add sensor functionality. One of the major advantages of bioactive paper sensors is that they are designed to operate without sophisticated equipment [6]. Generally the sensitivity is tolerated at the expense of simple applications compared to other analytical methods. In bioactive paper biosensors, enzyme-immobilized paper is the matrix for fluid sample transportation, biological detection, and the detection in a single step process. For paper-based biosensors, a variety of colorimetric formats have been developed including dipstick techniques and lab-on-paper microfluidic systems.