This paper describes novel adaptations of optically sectioned planar format assays to screen compounds for their affinities to materials surfaces. The novel platform, which we name Optical sectioned Indicator Displacement Assays (O-IDA), makes use of displaceable dyes in a format adaptable to high-throughput multi-well plate technologies. We describe two approaches; the first being where the dye exhibits fluorescence in both the surface bound and unbound state and the second, where fluorescence is lost upon displacement of the dye from the surface. Half maximal inhibitory concentration (IC50), binding affinity (Ki), and binding free energy (∆Gads) values can be extracted from the raw data. Representative biomolecules were tested for interactions with silica in aqueous environment and ZnO (0001)-Zn and (10-10) facets in a non-aqueous environment. We provide the first experimental values for both the binding of small molecules to silica and the facetdependent ZnO binding affinity of key amino acids associated with ZnO-specific oligopeptides. The specific data will be invaluable to those studying interactions at interfaces both experimentally and computationally. O-IDA provides a general framework for the high-throughput screening of molecules binding to materials surfaces, which has important applications in drug delivery, (bio-) catalysis, biosensing and biomaterials engineering.

We describe a surface charge imaging method for heterogeneous biosilicas based on relationships between zeta (ζ) potential, feature size of nanoparticles, and PDMPO fluorescence and apply it to silicified structures...