Paper-Based ELISA: A Novel Diagnostic Approach for Monitoring Aqueous Humour VEGF Level in Ocular Diseases

Abstract

We commonly diagnose ocular diseases via both morphological changes and symptoms. It is necessary to develop biochemically based assays for early or follow-up diagnosis of these diseases with a focus on robustness and ease of handling. To lay out a prospective path toward this goal, we describe and propose the use of ultrahigh sensitive paper-based ELISA (p-ELISA), which uses a treated piece of filter paper to monitor the activity of ocular diseases (i.e., detecting the vascular endothelial growth factor (VEGF) concentration in aqueous humour for prolifera-tive diabetic retinopathy or age-related macular degeneration diagnosis). The advantages of p-ELISA include the following: (1) the capacity to directly measure biomarker concentrations in aqueous humour using only a tiny sample volume (as little as 2 μL); (2) significantly increased sensitivity compared to conventional ELISA (fg/mL levels); and (3) inexpensive materials and a short operation duration. P-ELISA is a novel point-of-care diagnostic tool with the significant potential to advance ophthalmological treatment guidelines by facilitating early detection and routinely monitoring therapeutic response.