Real-time prostate-specific antigen detection with prostate-specific antigen imprinted capacitive biosensors

Prostate specific antigen (PSA) is a valuable biomarker for early detection of prostate cancer, the third most common cancer in men. Ultrasensitive detection of PSA is crucial to screen the prostate cancer in an early stage and to detect the recurrence of the disease after treatment. In this report, microcontact-PSA imprinted (PSA-MIP) capacitive biosensor chip was developed for real-time, highly sensitive and selective detection of PSA. PSA-MIP electrodes were prepared in the presence of methacrylic acid (MAA) as the functional monomer and ethylene glycol dimethacrylate (EGDMA) as the cross-linker via UV polymerization. Immobilized Anti-PSA antibodies on electrodes (Anti-PSA) for capacitance measurements were also prepared to compare the detection performances of both methods. The electrodes were characterized by atomic force microscopy (AFM), scanning electron microscopy (SEM) and cyclic voltammetry (CV) and real-time PSA detection was performed with standard PSA solutions in the concentration range of 10 fg mL(-1) -100 ng mL(-1). The detection limits were found as 8.0 x 10(-5) ng mL(-1) (16 x 10(-17) M) and 6.0 x 10(-4) ng mL(-1) (12 x 10(-16) M) for PSA-MIP and Anti-PSA electrodes, respectively. Selectivity studies were performed against HSA and IgG and selectivity coefficients were calculated. PSA detection was also carried out from diluted human serum samples and finally, reproducibility of the electrodes was tested. The results are promising and show that when the sensitivity of the capacitive system is combined with the selectivity and reproducibility of the microcontact-imprinting procedure, the resulting system might be used successfully for real-time detection of various analytes even in very low concentrations. (C) 2015 Elsevier B.V. All rights reserved

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