Development of screen- printed carbon electrode-based immunosensors for the electrochemical detection of dengue virus antigen

Objective: This study describes the development of a cost-effective and sensitive immunosensor for rapid detection of the dengue virus (DENV) antigen in human plasma. Methods: Screen-printed carbon electrodes (SPCEs) were used to fabricate the immunosensor by immobilizing the DENV antibodies to its surface using 1-ethyl-3-(3-dimethylamino propyl)carbodiimide hydrochloride/N-hydroxysulfosuccinimide (EDC/s-NHS) as linker. The detection of the antigen–antibody interaction was achieved by linear sweep voltammetry (LSV) using potentiostat instrument and a sensor connector. The developed method was validated as per the ICH guidelines for linearity, sensitivity and accuracy. Results: The developed immunosensors showed excellent sensitivities in detecting the DENV antigens in both phosphate buffer saline (PBS) maintained at pH 7.4 as well as diluted human plasma. The limit of detection (LOD) values obtained in PBS was 0.11 nM; whereas in human plasma, it was calculated to be 0.16 nM. Good linearity was obtained for both PBS and human plasma over a wide range of concentrations showing promising applications of the immunosensor in both qualitative and quantitative detection of dengue virus antigen. Also, the developed immunosensor was able to detect the dengue antigen in 5 min showing rapid detection. Conclusion: A sensitive, reliable and cost-effective biosensor was developed which was able to detect the dengue virus antigen selectively and rapidly