Gold-Enhanced Multielectrode Electrochemical Immunosensor for Rapid Electrochemical Detection of Dengue NS1

Dengue is one of the most widespread viral diseases in the world, transmitted mainly by Aedes aegypti and Aedes albopictus. In tropical and resource-limited regions, rapid and accurate diagnostic tools are of utmost importance, especially when aiming for effective control, but current detection methods face limitations in sensitivity, specificity, or accessibility. In this work, a multielectrode disposable electrochemical immunosensor was developed for the detection of the nonstructural protein 1 (NS1), an early biomarker of dengue infection. This device presents four fully individual and functional working electrodes modified with gold nanoparticles. This configuration enables replicate measurements and improved reproducibility within a single platform while using minimal sample volume. The electrodeposition of Au nanoparticles was optimized through Design of Experiments approaches, allowing the system to suitably determine the target protein with a specific biorecognition architecture based on antibody–antigen recognition. This biosensor was characterized by morphological and electrochemical techniques, achieving a linear response between 1.0 and 200 ng mL–1 and a limit of detection of 0.34 ng mL–1. Afterward, human serum samples spiked with NS1 showed recovery rates between 96.6% and 115%. All results indicate that the proposed multielectrode immunosensor is a promising, label-free, and portable diagnostic alternative for NS1 determination while maintaining a relatively low cost and simple preparation.