Detection of α-Methylacyl-CoA Racemase in Serum and Urine Using a Highly Sensitive Electrochemical Immunodetector

The detection of alpha-methylacyl-CoA racemase (AMACR), a novel biomarker for prostate cancer, is demonstrated in serum and urine using a novel immunodetection method. The detection system consists of a three-electrode conventional electrochemical cell modified with a gating electrode for applying a gating voltage V-G to the immune complex immobilized on the working electrode to provide signal amplification. The detection system is realized by integrating gating electrodes with screen-printed electrodes. This detection method does not require involved sample preparation procedures. The detection was demonstrated in serum and urine samples on the nanogram/mL level with V-G equal to 0.6 V. Detection in serum was also performed on the picogram/mL level with a limit of 100 picogram/mL with V-G=0.6 V being a necessary condition.