Development of immunochips for the detection of dengue viral antigens

Abstract

Recently, dengue virus has become a new emerging disease in the world. However, the procedures currently used for the detection of dengue virus are cumbersome and time-consuming. This is unfavorable for early stage epidemiological control and effective medical treatment. A new detection system was developed based on the quartz crystal microbalance (QCM) coating using two monoclonal antibodies that act specifically against the dengue virus envelope protein (E-protein) and non-structural 1 protein (NS-1 protein), respectively. Three different immobilizing methods, the glutaraldehyde (GA) method, protein A method and carbodiimide method (1-ethyl-3-(3-dimethyl- aminopropyl) carbodiimide, EDC) were used to prepare the immunochips. The “cocktail” immunochip, which has both antibodies attached, was also fabricated and used in comparison. The results showed that the protein A method was the best among the three. The sensitivity of the immunochip was 100-fold greater than the conventional sandwich ELISA method. The cocktail immunochip had a higher signal level than the normal immunochip. The time required for detection was shorter (about 1 h) and a blood specimen could be used to detect the virus in the viremia phase.