Electrobiofabrication of antibody sensor interfaces within a 3D printed device yield rapid and robust electrochemical measurements of titer and glycan structure.

We report the integration of 3D printing, electrobiofabrication, and protein engineering to create a device that enables near real-time analysis of monoclonal antibody (mAb) titer and quality. 3D printing was used to create the macroscale architecture that can control fluidic contact of a sample with multiple electrodes for replicate measurements. An analysis "chip" was configured as a "snap-in" module for connecting to a 3D printed housing containing fluidic and electronic communication systems. Electrobiofabrication was used to functionalize each electrode by the assembly of a hydrogel interface containing biomolecular recognition and capture proteins. Specifically, an electrochemical thiol oxidation is used to assemble a thiolated polyethylene glycol hydrogel, that in turn is covalently coupled to either a cysteine-tagged protein G that binds the antibody's Fc region or a lectin that binds the glycans of target mAb analytes. We first show the design, assembly, and testing of the hardware device. Then, we show the transition of a step-by-step sensing methodology (e.g., mix, incubate, wash, mix, incubate, wash, measure) into the current method where functionalization, antibody capture, and assessment are performed in situ and in parallel channels. Both titer and glycan analyses were found to be linear with antibody concentration (to 0.2 mg/L). We further found the interfaces could be reused with remarkably similar results. Because the interface assembly and use are simple, rapid, and robust, we suggest this assessment methodology will be widely applicable, including for other biomolecular process development and manufacturing environments.