Challenges and perspectives in the development of paper-based lateral flow assays

Lateral flow assays (LFAs) have been introduced and developed over the last half century. This technology is widely used as a tool for diagnosis in several fields such as environment, food quality and healthcare. Point-of-care (POC) diagnosis using LFAs has been attracting attention of the research community, particularly aiming for the development of a platform that can evaluate of biological markers in bodily fluids such as saliva and urine. The existence of a disease or the pregnancy can be determined by a test device, before further investigation and medical treatment. LFAs make use of a disposable test strip, which can provide diagnosis result on the spot within minutes. Thus, LFAs is a promising alternative of preliminary diagnosis for laboratory instruments that are costly, time consuming and require trained personnel. This paper includes a brief overview of the conventional LFAs: material selection based on its roles and characteristics, working principles, fundamentals, applications, and design criteria. We mainly discuss the technical challenges in both engineering and biochemical aspects and recommends possible solutions. We identify current research trends and provide perspectives of advanced technologies for enhancing assay performance.