Paper-based biosensors: Overview from past to future

Abstract

Paper-based biosensors offer a prudent platform for medical diagnostics. In the past, filter paper has been used as a substrate for fabrication of litmus paper strips, which is an example of a primitive chemical sensor. But recently paper-based biosensors have evolved to the extent that they can detect many diseases and their associated biomarkers. Many applications in the field of point-of-care (POC) diagnostics use paper-based materials as a substrate for fabricating various biosensors. Since paper is versatile, porous and flexible it can serve as a substrate for the construction of various biosensors. This tunable porosity facilitates the capillary action-governed movement of the fluids. Hence, paper is also a great material to fabricate microfluidic devices. Recently, paper-based biosensors have started emerging and are still evolving. Various formats of these biosensors such as lateral flow assay devices (LFAs), microfluidic paper-based analytical devices (µPADs) and dipsticks were developed in the past and are still improving. This chapter will briefly focus on the journey of paper-based biosensors since their inception to recent advancements in the field.