A Rapid Electrochemical Paper-Based Quantification Diagnostic Kit for an Early Test of Dengue NS1 Protein Biomarker

The development of a rapid, affordable, and sensitive diagnostic kit for point-of-care is important in most healthcare settings. Our technology aims to provide quantification of viral biomarkers whose core is the proprietary formulated electroactive immunonanoparticles that bind to the target biomarker and subsequently move along toward the biofunctionalized screen-printed gold electrodes (SPGE) to generate an amperometric signal, amalgamating the concepts of lateral flow with the glucometer. The SPGE functions simultaneously as a signal transducer and a solid-state support for a sandwich ELISA-like immunoassay. The successful immunocomplex formation is then recorded electrochemically using a potentiostat, whereby the signal was contributed by a hydrophilic redox label present, radical TEMPO (TEMPO•), on the formulated nanoparticles. The stability of the formulated nanoparticles was studied for 20 nm gold colloidal nanoparticles (AuNPs) and a special stabilizing ligand, polyethylene glycol (PEG) polymer, which was incorporated to not only prevent the salt-mediated AuNPs aggregations, but also provide an anchor for antibody and redox species conjugation. To-date, we have successfully developed a miniaturized 3D-printed prototype device that is able to sensitively detect and quantify dengue NS1 protein in both buffered and clinical samples in less than 30 minutes. The validation of positive and negative samples was further performed with ELISA which means that the development of the prototype is a promising start as a point-of-care diagnostics technology.