Immunodetection of cancer marker in human serum using silicon field effect transistors
A. Kim, C.S. Ah, C.W. Park, J.-H. Yang, T. Kim, C.-G. Ahn, G.Y. Sung
Electronics and Telecommunications Research Institute, KR
Keywords: biosensor, cancer marker, field-effect transistor, carcinoembryonic antigen
Abstract:Label-free and real-time carcinoembryonic antigen (CEA) sensor has been developed using p-type silicon field-effect transistor (FET) where the conventional “top-down” semiconductor processes were employed to make nanostructures. We have detected the CEA as a marker for colorectal cancer1 in undiluted human serum with high salt concentration (~150 mM) using the Si-FET. To detect the CEA, the monoclonal antibody of CEA (anti-CEA) has been immobilized on the Si surface through covalent linkage using specific surface chemistry. Specific binding of CEA with the anti-CEA on p-type Si-FET channels leads to a conductivity change in response to variations of electric field at the surface, which results in label-free and real-time immunodetection. It has been known that detecting a target antigen in human serum is difficult because of short Debye screening length of the serum with high salt concentration.2 In this presentation, we discuss new detection method of the target antigen, CEA, in human serum and show quantitative detection results of CEA in human serum from 1 ng/mL to 100 ng/mL using the Si-FET sensor.