POROUS POLYMERS AND DESIGNED SORBENTS FOR APPLICATIONS IN BIOMEDICAL RESEARCH

Sammanfattning: Everyday millions of bioanalyses are performed in clinical laboratories, hospitals and research centers, where technicians and bio-analysts utilize analytical chemistry principles and instruments to serve medicine and biomedical research. A method routinely used for sample preparation in bioanalysis is solid-phase extraction (SPE). SPE is a simple method to extract an analyte from a sample matrix based on the use of solid particles, but the design of these solid particles is a challenging process dependent on the application. However, polymer sorbents are particularly attractive as they are robust materials that can be specifically synthesized for a target application. Designing polymer sorbents involves controlling the morphology of polymeric particles in terms of shape, rigidity, porosity and surface area as well as the functionalization of the surface which greatly influences their affinity to the target analyte. In Paper I, a method to control the porosity of polymers was developed. The creation of a structured, uniform, reproducible and solvent-independent porosity was achieved by using fumed silica nanoparticles – a solid material that aggregates in a filamentous way, shaping a well-connected three-dimensional structure that served as template for the porosity of the polymers. In Paper II, this method was adapted to the synthesis of molecularly imprinted polymers (MIPs) for the separation of ephedrine enantiomers. In Paper III, phosphotyrosine was immobilized on the surface of fumed silica nanoparticles which were used as solid porogen for the synthesis of phosphotyrosine MIPs. The MIPs were used as solid-phases in a sample preparation method targeting phosphopeptides. In Paper IV, a problem related with the extraction of an alcohol consumption biomarker was addressed. New solid-phases targeting phosphatidylethanol (PEth) were synthesized and tested with plasma and human blood. The polymers were able to retain and release PEth with a simple extraction protocol which proved their potential to be used in clinical analysis.