Controlled Silanization: Novel Functional Silatrane Assemblies from Material Synthesis、Surface Grafting Mechanism and Implementation for Molecular Diagnosis(1/3)

“Controlled silanization” is an approach to harness the grafting density, thickness, roughness, molecular orientation and reproducibility of organosilicons on surfaces. However, the considerable susceptibility of organosilicons to moisture and temperatures, leading to fast hydrolysis and condensation of silane groups, remains problematic for a wide range of applications. The formation of polysiloxane aggregates in solutions and surfaces contributes to thick, inhomogeneous and chemically unstable organosilicon coatings on surfaces, deteriorating the modification quality. As advance in nanomaterials and nanodevices, lack of “controlled silanization” hampers the commercialization of silicon-based devices due to compensated surface functions and un-reliable manufacturing process. Field-effect transistor-based biosensor (Bio-FET), for example, exhibits a narrow probing distance of 1~10 nm and the sensitivity decays exponentially with the distance from the surface. Therefore, a thick and inhomogeneous coating on the sensor surface can compromise the detection performance. Accordingly, in this proposal, we will develop a set of novel antifouling and functionalizable silatrane assemblies that contain tricyclic caged silatranyl ring and transannular N → Si dative bond. The unique structure of organosilatranes gives rise to excellent chemical stability in presence of water and facilitates post-synthesis. In this work, a set of functional organosilatranes, carrying amine, mercapto, zwitterionic antifouling sulfobetaine and functionalizable carboxylate groups, will be developed. We attempt to investigate molecular assembling process of silatranes on surfaces and to verify surface characteristics and to establish highly flat, compact, chemically stable, good orientated and reproducible biointerfaces for molecular detection in complex medium. The efforts will further enhance the specificity and sensitivity of a biosensor. The intact contour of “silatrane surface chemistry” will be developed for their great scientific potentials and a wide spectrum of applications. Self-assembling materials have been greatly influential to surface science. The proposal will be devoted to “controlled silanization”. Studies from different angles will boost the advances in surface chemistry, biomaterials and nano-sciences. Last but not least, the outputs of the research will generally affect the establishment of special chemistry industries and development of high-level talents.