Separation of beta-human chorionic gonadotropin from fibrinogen using a MEMS size exclusion chromatography column

This article reports a MEMS (Micro-ElectroMechanical-Systems)-based column separator designed for potential integration with portable medical point-of-care testing (POCT) devices. The MEMS column uses size exclusion chromatography (SEC) to pre-separate raw samples by size, and is made of polydimethylsiloxane (PDMS) fabricated on a glass slide. The MEMS SEC column separates 300 ng/mL of beta-human chorionic gonadotropin (b-hCG), a cancer biomarker, from a fibrinogen-rich solution (20 lg/mL) in 10 min, showing 2.12 resolution and 0.036 mm plate height through fluorescent detection. Results are further verified by b-hCG and anti-bhCG antibody conjugate using surface plasmon resonance (SPR). The collected b-hCG-rich eluent at 8 min shows 11 mDeg of angle shift. The fluorescent detection and SPR results demonstrate the complete discrimination of b-hCG from fibrinogen using the MEMS SEC column, and illustrate its viability for integrating a sample preparation stage in POCT devices to assist cancer screening and prognosis.