Label-free optical monitoring of proteolytic reaction products using nanoporous silica colloidal assembly

An optical biosensor for rapid monitoring of proteolytic activity is constructed by immobilization of pro teases onto multifunctional silica colloidal assembly (SCA). The SCA serves as Fabry-Perot thin film, which is highly sensitive to the presence of biomolecules (e.g., enzymes, proteins and short peptides) within the nanostructure. Moreover, the SCA acts as a size-exclusion element, allowing to entrap and to concentrate the enzymatic degradation products for downstream mass spectrometry analysis for substrate profiling and cleavage sites identification. (C) 2018 Elsevier B.V. All rights reserved.