In this work, we report a develop of electrochemical immunosensor based on ZnO nanostructures immobilized with ZIKV-NS1 antibody on Printed Circuit Board (PCB). ZnO nanostructures were grown on PCB by chemical bath deposition (CDB) and characterized by SEM. ZIKV-NS1 antibody was immobilized on the ZnO nanostructures surface via cystamine and glutaraldehyde. The samples were characterized by Immunofluorescence Confocal Microscopy and FTIR to identify the immobilization of the antibody to the sensor board. The analytical responses of the immunosensor were evaluated by Cyclic Voltammetry (CV). The biosensor developed here allows rapid detection of Zika virus in undiluted urine, without cross reactive with DENV-NS1 antigen, with linear range 0.1 ng mL(-1) to 100 ng mL(-1). The limit of detection is lower than 1.00 pg mL(-1). The biosensor is portable, cost-effectiveness, and simple to use, which makes it ideal for point-of-care applications.

Background Rapid diagnosis tests (RDTs) are easy to carry out, provide fast results, and could potentially guide medical treatment decisions. We investigated the performance of a commercially available RDT, which simultaneously detects the non-structural 1 (NS1) dengue virus (DENV) antigen, and IgM and IgG DENV antibodies, using representative serum samples from individuals in a dengue endemic area in Salvador, Brazil. Methodology/Principal findings We evaluated the accuracy of the SD BIOLINE Dengue Duo RDT (Abbott, Santa Clara, USA; former Alere Inc, Waltham, USA) in a random collection of sera. Samples included acute-phase sera from 246 laboratory-confirmed dengue cases and 108 non-dengue febrile patients enrolled in a surveillance study for dengue detection, 73 healthy controls living in the same surveillance community, and 73 blood donors. RDT accuracy was blindly assessed based on the combined results for the NS1 and the IgM test components. The RDT sensitivity was 46.8% (38.6% for the NS1 component and 13.8% for the IgM component). Sensitivity was greater for samples obtained from patients with secondary DENV infections (49.8%) compared to primary infections (31.1%) (P:0.02) and was also influenced by the result in the confirmatory dengue diagnostic test, ranging from 39.7% for samples of cases confirmed by IgM-ELISA seroconversion between paired samples to 90.4% for samples of cases confirmed by a positive NS1-ELISA. The RDT specificity was 94.4% for nondengue febrile patients, 87.7% for the community healthy controls, and 95.9% for the blood donors. Conclusions/Significance The SD BIOLINE Dengue Duo RDT showed good specificities, but low sensitivity, suggesting that it may be more useful to rule in than to rule out a dengue diagnosis in dengue endemic regions.