Paper Based Microfluidic Colorimetric Sensor Systems

Chemical sensor systems is a multidisciplinary field that stands out as a good example of progress in science and technology. Chemical sensors are analytical devices in which the sensing layer, transmission system and signal reading systems are integrated. It has to have criteria such as high sensitivity and selectivity, low cost, easy to use, portability. Basic science and engineering are used to meet the criteria. One of the important structures that provide great advantages in sensor systems and the product of multidisciplinary studies is microfluidic systems. Microfluidic systems are the technology of producing channel structures ranging from 100 nm to 100 µm with different material types such as polydimethylsiloxane (PDMS), glass, and paper. Although each material has its own advantages and disadvantages, it is seen that the applications of μPAD chemical sensors in different fields such as wearable, clinical, food and environment are increasing day by day with the breakthrough studies carried out by the Whitesides Group with Paper-Based Microfluidic (µPAD) Sensors in 2007. In this review article, the history of paper-based microfluidic systems, patterning of paper and chemical sensor applications are presented.