Abstract
The present work is a proof-of-concept study that nanodroplet microfluids technology is a tool for the quality control of monoclonal antibodies (mAb). The aqueous nanodroplets mixing on-demand inside the microfluidic channel permts to perform ensymatic reactions in an automated and controlled manner. First of all, nanodroplets generation and mixing were optimized regarding the choice of organic solvent and pressures applied on inlet ports. This optimization phase permits to perfectly control the amount of each reactant mixed in each nanodroplet. Then, in-line degradation of fluorescein isocyanate (FITC) in presence of the Horseradish peroxidase (HRP) enzyme was realized in a microchannel to show the ability of nanodroplet microfluidics technology to generate biochemical reactions. Enzymatic reactions involving trypsin and a monoclonal antibody (trastuzumab) (bottom-up approach) were also realized at a different enzyme to substrate (E/S) ratio by controlling the nanodroplets volume mixed inside microchannels. The determination of the amount of HRP grafted on the active binding sites of mAb surfaces (labeled molecule used in analytical biochemistry assay) was also realized. Successful and repeatable reactions were obtained demonstrating the power of the proposed methodology.