Multiplex Viral Detection Platform Based on a Aptamers-Integrated Microfluidic Channel.

A polydimethylsiloxane-based microfluidic device has been developed for the multiplex detection of viral envelope proteins such as Zika and chikungunya on a single platform using aptamer-analyte interactions. The channel is integrated with microsized pillars that increase the surface area allowing more aptamers to attach to the incoming envelope protein molecules, thus increasing the overall sensitivity of the system. The working of the device depends on the formation of protein-mediated sandwich morphology that is obtained using an aptamer and aptamer-functionalized gold nanoparticle (AuNP) pair. The colorimetric signal is obtained upon introduction of silver reagents into the channel, which are selectively deposited on the AuNP surface, providing a gray contrast in the testing zone. The microfluidic channel approach successfully detected clinically relevant concentrations of Zika and chikungunya envelope proteins in phosphine-buffered saline (1 pM) and calf blood (100 pM) with high specificity using gold-decorated aptamers integrated in a microfluidic channel.