A gold nanoparticle-based microfluidic protein chip for tumor markers.

A cancer protein chip has been developed incorporating with signal amplification technology based on gold nanoparticles (AuNPs) and microfluidic technology. The chip was a reversed phase one that deposited the target proteins directly onto chip surface. At first, a tumor marker protein, carcinoma embryonic antigen (CEA), was captured on the chip with the help of first layer microfluidic channel. Then, monoclonal antibody was reacted with the CEA through the second layer microfluidic channel at upright direction against the first layer. In the end, AuNPs labeled secondary antibody and silver enhancement regent were added to creating positive or negative signals in crossed areas, depending on the amounts of tumor marker protein. Using the protein chip based on nanotechnology, we could detect CEA at a wide range of concentration (5-50,000 ng/mL) and also had high sensitivity (LOD < 1 pM). Because of its quick detection procedure and no need for high-cost instruments, the protein chip showed potential use for point-of-care (POC) diagnostics.