Microcontact imprinting based surface plasmon resonance (SPR) biosensor for real-time and ultrasensitive detection of prostate specific antigen (PSA) from clinical samples

Prostate specific antigen (PSA) is an important biomarker for diagnosis and prognosis of prostate cancer. Herein, microcontact PSA-imprinted surface plasmon resonance (SPR) sensor chip was developed for sensitive, real-time detection of PSA. The imprinted chip was prepared in the presence of methacrylic acid (MAA) as functional monomer and ethylene glycol dimethacrylate (EGDMA) as cross-linker via UV polymerization using microcontact imprinting technique. PSA imprinted SPR sensor chip was characterized by atomic force microscope (AFM), scanning electron microscope (SEM), ellipsometry, dispersive Raman and Fourier transform infrared spectroscopy (FT-IR). Under optimal conditions, PSA detection was performed with standard PSA solutions in the concentration range of 0.1-50 ng mL(-1) with a detection limit (LOD) of approximately 91 pg mL(-1) (18 x 10(-14) M). Selectivity studies were performed against human serum albumin (HSA) and lysozyme (Lyz) as the competitive agents. The developed system was evaluated for analysis of 10 clinical serum samples and showed approximately 98% agreement between the results obtained by commercial enzyme-linked immunosorbent assay (ELISA) method without significant differences at the 0.05 significance level (p = 0.751, p >0.05). (C) 2015 Elsevier B.V. All rights reserved.