The proposed research aims to develop a new scientific instrument for nanometer scale biochemical measurement based on the integration of nanoparticle bioconjugate chemistry and atomic force microscopy (AFM). The marriage of AFM and nanoparticle chemistry brings together the most widely used tool for nanotechnology (AFM) and one of the most promising techniques for nanoscience (nanoparticle chemistry). Within the one-year NER framework, the team (comprised of researchers in nanoparticle chemistry and atomic force microscopy) will demonstrate the fabrication and operation of AFM cantilevers with integrated, chemically active nanoparticle tips to probe ligand-receptor interactions. Receptor driven cellular behavior represents an important and diverse class of functional structures in biological systems. Receptors are uniquely suited to direct such processes due to their ability to sense the environment through ligand binding and their ability to transmit this signal to the cell interior via signal cascades. The goal of this proposal is quantitatively measure the interactions between ligands and their biological receptors. Currently, the study of these fundamental biological components is limited by available ensemble imaging tools such as radiolabeled ligands or indirect detection via antibodies. This particular measurement holds the promise of providing heretofore unobtainable resolution of ligands binding to cellular receptors. It is anticipated that the developed technique will offer new opportunities to probe fundamental aspects of receptor function, develop novel approaches to drug screening and implement new technologies for the interrogation of biochemical systems. Specifically, we will:
1. Develop methods for the functionalization of an Atomic Force Microscope cantilever tip with silica nanoparticles.
2. Design, synthesize, and characterize novel nanoconjugate silica nanoparticles in situ on the cantilever tip.
3. Investigate the forces in receptor-ligand interactions through adhesion, tapping and lateral force microscopy measurements, with the goal of measuring single-molecule interactions.
