研究期間：10108~10207;XI. Chinese and English abstracts of research project: Please brief the key points of your project and provide the key words according to the nature of your project. (I ) English abstract (in 500 words) Applications of biosensors to complex media remain a tremendous challenge due to high false-positives from nonspecific protein adsorption and limited sensitivity from low ligand loading. Despite extensive efforts, exiting surface platforms are able to solve one of these two problems (i.e. specificity or sensitivity) separately, but not both together. Two-dimensional (2D) surface platforms based on dual-functional zwitterionic poly(carboxybetaine) (PCB) from the PI5s group are able to achieve ultra low fouling from undiluted blood plasma or serum, but with limited antibody loading. Three-dimensional (3D) surface platforms such as the carboxymethylated dextran-based matrix from BIAcore™ (GE) are able to achieve very high antibody loading, but with high fouling in complex media due to their loose structures. The objective of this work is to develop a unique strategy for sensing surfaces by integrating 2D and 3D structures so as to achieve BOTH low nonspecific binding and high antibody loading. In this work, the PI proposes a “two-layer” architecture which combines one highly dense PCB layer on the bottom, to achieve ultra low fouling, with one “loose” PCB layer on the top to achieve a high antibody binding capacity. Three specific tasks are proposed: (1) to develop the “two-layer” architecture based on PCB films via the “graft-from” approaches of surface-initiated atom-transfer radical polymerization (ATRP) and photoiniferter-mediated polymerization (PIMP); (2) to synthesize defined PCB polymer chains in solution and then graft the chains to an initial PCB brush layer via “click” and “thiol-ene” chemistries; (3) to evaluate the “two-layer” PCB films for their nonfouling, immobilization efficiency and stability, and bioactivity from complex media. Results will be compared with those from the benchmark of carboxymethylated dextran-based surface chemistries from BIAcore™ (GE). It should be pointed out that while this “two-layer” platform will be demonstrated with PCB, this is a powerful and yet generic concept which can be applied to other surfaces chemistries, such as dextran or poly(ethylene glycol)-based materials. However, the superior properties of dual-functional (nonfouling and functionalizable) PCB materials will make the proposed “two-layer” PCB film the most ideal platform for diagnostic applications in complex media. Although this work will be demonstrated using a surface plasmon resonance biosensor, it will be easily adaptable to other sensing platforms and devices. This work has a broad range of impacts for many applications from early cancer diagnostics to food safety monitoring. The success of this work will transform the field of biosensing.
