In chapter one, we designed, synthesized and characterized two cysteine sensors CCPAP and CCPAN, with improved water solubility, cell penetration ability, and potential targeting selectivity. Two types of positive charged groups, i.e. triphenylphosphonium and pyridinium were introduced respectively to the frame structure CCP by coupling carboxylic acid with amine to improve the cell permeability and cysteine selectivity. ESI-MS, NMR and IR were employed to characterize the molecular structures of the two novel probes. These probes have better water solubility than the parent molecule DCP, and better cell penetration capability than CEP, which could further distinguish the cysteine concentration differences in living cells. Thus, the probes might be used in the quantitative measurement of mitochondrial cysteine concentration as well as the real-time monitoring of related physiological effects of cysteines in living cell.

In chapter two, three polymers, i.e. P4VP, PCL-Py homopolymer and P(CL-g-Py)-ran-PCL random polymer were employed to assemble with beta-glucuronidase ( BGus) to form polymer-protein core-shell particles with controlled size. We found that the pyridine grafted polymers could preserve the structure and functionality of BGus. The activity, thermal stability and storage stability of assembled BGus were comparable to free BGus in the solution.