Detection of tumor marker in blood serum using antibody-modified field effect transistor with optimized BSA blocking

This paper demonstrates that antibody-modified field effect transistors (FETs), which were treated with bovine serum albumin (BSA) blocking, had quantitative capability for tumor marker detection in blood serum. Antibody-modified surface covered with 0.1% BSA effectively minimized nonspecific adsorption of blood proteins. Tumor markers with their isoelectric points of around 5 generated strong signals in body environmental pH (pH 7.4) in proteins with isoelectric points ranging from 3 to 10. Detection of a tumor marker alpha-fetoprotein in blood serum at required level for clinical diagnosis (10 ng/mL) was achieved. The obtained results suggest that the fabricated FETs be expected to practical application in medical fields for direct detection of multi-tumor markers from blood.