Applications of a Novel Multi-Parametric/Multimodal Spectroscopy Apparatus on Characterization of Functional Interfaces

Abstract

Multiparametric/Multimodal spectroscopy (MPMS), the integration of surface plasmon resonance, fluorescence, and electrochemistry based approaches provides new insights and complementary information about functional interfaces. In detection of biologically important analytes, MPMS is a promising tool, capable to provide a valuable cross-validated data in many important applications, and particularly in disease diagnosis. We have developed an integrated MPMS instrument and optical fiber spectral probe for simultaneous collection of all three parameters to quantify the components and kinetic parameters in the assembly of various functional interfaces, including covalent binding, layer-by-layer assembly, aptamer-based Electrochemical Proximity Assay (ECPA) and antibody-based ECPA. The instruments’ 3D printed flowcell integrated with multimode optic fiber, excitation laser sources (660nm), and sensing electrodes capable to record the SPR spectra, fluorescence and electrochemical data on the same platform. We have designed ECPA model system and obtained SPR signal that gives a comprehensive information about all steps of assembly, fluorescence signal corresponds specifically to the fluorophore labeled moieties, while electrochemistry will allow highly sensitive quantitative characterization of target analyte. This work not only provides quantitation information for protein targets, but allows a fundamental understanding of the kinetics in the formation of ECPA with an unprecedented level, which can overcome several key limitations of current, widely-used surface characterization technologies.