| Molecular recognition is of fundamental importance to the understanding of every aspect of life. Most of the biomolecular recognition processes operate at interfaces. By developing engineered surfaces and detection tools, this dissertation was performed with a primary focus of not only illustrating and understanding the inherent molecular recognition strategies employed by nature, but also utilizing them to develop more powerful research tools and improve the quality of life.; Biomolecular interactions at interfaces are dynamic events. Surface plasmon resonance (SPR) sensor is attractive for its ability of monitoring molecular interactions in real time and with high sensitivity. In this dissertation, different surface engineering methods were developed for applying SPR sensors in biosensor and biomaterial researches.; Surface engineering methods, including protein contact printing, patterned plasma deposition, and orthogonal self-assembly, were applied onto a novel overlayer SPR sensor, for developing it towards a self-referencing biosensor. These methods were shown to be effective for patterning surface functionalities on the adjacent gold and tantalum pentoxide surfaces of the SPR sensor. These functionalized overlayer SPR biosensors demonstrated ability of referencing bulk refractive index changes in complex biological solutions. The radio frequency plasma deposited tetraglyme thin films showed superior non-fouling properties, tested by up to 40mg/ml BSA and 100% human plasma.; To apply SPR to biomaterial research, an apatite-like mineral film was also grown onto the gold surface through surface-induced mineralization (SIM) method. The bulk of the mineral was identified as carbonated apatite. Observed by TOF-SIMS and XPS, the outermost layers of the mineral films were dominated by octacalcium phosphate (OCP), with minor apatite mixture. The results perhaps provide the first experimental evidence for a layer-by-layer OCP growth/hydrolysis mechanism of HAP formation.; The apatite mineral films were continuous and SPR active. By using the apatite-coated SPR sensor, interactions of phosphorylated osteopontin (POPN), non-phosphorylated osteopontin (NOPN), and bovine serum albumin (BSA) with the mineral surfaces were studied continuously. Upon adsorption, POPN demonstrated an inhibitory effect on further mineral deposition. NOPN, however, probably induced more rapid mineral deposition. BSA had similar effect as NOPN, but far less dramatic. |
