Microfluidic synthesis of ZIF-67 nanoparticles has emerged as a promising strategy for producing stable and monodisperse nanomaterials. These porous, pH-sensitive nanoparticles exhibit instability in acidic environments but remain stable in neutral and basic conditions. The precursors for ZIF-67 synthesis are water-soluble, enabling the use of water as a mediating solvent. Hence, they are highly suitable for drug delivery applications, eliminating concerns associated with toxic solvents commonly employed in pharmaceutical synthesis. This study describes a microfluidic chip designed based on a specific architecture (i.e., split-and-recombine) for the microfluidic synthesis of ZIF-67 nanoparticles using water as a green solvent, while simultaneously encapsulating trastuzumab. The primary objective is to investigate the design, fabrication, and application of a chip for synthesis and drug loading, capable of producing ZIF-67 nanoparticles with high encapsulation efficiency for large-scale synthesis and implementation in drug delivery scenarios. The synthesized nanoparticles exhibited an average diameter of approximately 200 nm, with an encapsulation efficiency exceeding 90 %. Drug release profiles were evaluated at two pH values (i.e., 7.4 and 6.5) showing less than 50 % and about 78 % release, respectively, using the dialysis bag method and UV–VIS spectroscopy. Additionally, corresponding kinetic models were derived. Characterization techniques, including SEM, FTIR, and EDS, were employed to thoroughly analyze the synthesized materials.