We report a synthesis platform for manipulation, modification, and potential production of nanoscale reagents using microscale carrier particles confined to a longitudinal acoustic trap. Pairs of perforated “pseudo-walls” enhance the local acoustic pressure field to immobilize reaction substrates (polymeric or glass beads) from a heterogeneous suspension. Nodal regions (pressure minima) of the acoustic field are perpendicular to the inflow direction to enable continuous, contactless, serial chemical reactions on the microparticle surface for, e.g., antibody (Ab) attachment, alteration, and recovery. Here, we discuss the potential of longitudinal standing bulk acoustic wave (LSBAW) architectures for creation of antibody conjugates (ACs) at research and production scales. Results prove the feasibility of combining acoustic manipulation of microcarriers with steps constituting the synthesis and purification of ACs including mixing, washing, buffer exchange, conjugation reaction, and release/recovery. 10-μm diameter hollow glass spheres (HGS) were modified to create a Protein G-terminated self-assembled monolayer (SAM). Modified HGS were introduced and focused to the midline of the acoustic trap. Focused beads were then incubated with a solution of green fluorescent secondary antibodies (rabbit anti-goat IgG Alexa Fluor 488) for 45 minutes before flushing the channel with phosphate buffered saline (1xPBS). N- hydroxysuccinimide (NHS) chemistry was used to attach a sulfo-cyanine3 (Cy3) NHS ester dye to the immobilized antibodies to demonstrate a common conjugation technique. Finally, a low-pH release buffer was used for recovery. Flow cytometry and gel electrophoresis confirm successful AC assembly without damage due to ultrasound exposure. Potential scale-up strategies are also discussed.
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