A three-layer competition-based giant magnetoresistive assay for direct quantification of endoglin from human urine.

This study presents a three-layer competition-based assay for ultrasensitive detection and quantification of endoglin from unprocessed human urine samples using a giant magnetoresistive (GMR) sensor and high-moment magnetic nanoparticle-based biosensing technology. This biosensing platform detects as few as 1000 copies of endoglin at concentrations as low as 83 fM with high detection specificity and has a three-order dynamic range. The results reveal that endoglin levels in urine have the potential to predict for the presence of prostate cancer and to distinguish between prostate cancers of different grades.