Rapid real-time detection of procalcitonin using a microcontact imprinted surface plasmon resonance biosensor

Procalcitonin (PCT) is a promising biomarker for identification of the origin and severity of sepsis, which is a deadly body infection. In this work, we report the preparation of a surface plasmon resonance (SPR) biosensor which utilizes a molecular imprinted polymer surface for rapid and reliable detection of PCT. The molecular imprinted surface was prepared using a microcontact imprinting technique, in which PCT molecules were first immobilized onto a glass support and brought into contact with a solution of 2-hydroxyethyl methacrylate (HEMA) and ethylene glycol dimethacrylate (EGDMA) on a SPR sensor, then the polymerization process was performed. After removal of the PCT molecules, specific molecular recognition sites were obtained, where PCT molecules can selectively rebind, only at the surface of the polymer matrix. PCT detection studies were carried out using PCT solutions in phosphate buffer and simulated blood plasma (SBP) at different concentrations. The SPR biosensor can detect very low concentrations (9.9 ng mL(-1)) of PCT within approximately 1 h, in both phosphate buffer and SBP. High selectivity of the biosensor against PCT was also demonstrated in the presence of several competitive proteins such as human serum albumin, myoglobin and cytochrome c.