Direct Evaluation of Ligand-Receptor Interaction by a Novel Imaging Model Based on Fluorescent Silica Nanoparticle as Ligand Probe and Molecular Imprinting Polymer as Artificial Receptor

Abstract

A novel fluorescent imaging system was established to monitor ligand-receptor interactions. Fluorescent silica nanoparticles (FNPs) conjugated with ligand molecules were employed as ligands and molecular imprinting polymer (MIP) as artificial receptors in this work. Fluorescent silica nano-particles which have controllable and uniform size of 120 nm were synthesized and characterized by scanning electronic microscopy (SEM). The FNPs with excitation and emission peaks at 289 nm and 570 nm provide strong fluorescence intensity, excellent photostability, and easy surface modification. L-phenylalaninamide was employed as a test ligand and MIP template. By use of grafting initiator of 4,4′-azobis (4-cyanovaleric acid), a MIP receptor membrane was firmly grafted on the support layer by layer. Results showed that the specific affinity between artificial MIP receptor and ligand conjugated to the FNPs can be successfully monitored. It also suggests that the designed imaging system is suitable of studying molecular interactions and has a great potential for further application.

Keywords:

• Fluorescent probe
• Ligand-receptor interaction
• Molecular imprinting
• Nanoparticles

Acknowledgments

This work was supported by the National Scientific Foundation of China (NSFC Nos. 20775055, 30973672 and 90817103), the Important National Science & Technology Specific Projects (No. 2009ZX09301-14), the Fundamental Research Funds for the Central Universities and the start-up funding for Luojia Chair Professorship of Wuhan University.