A 3-D Printed Microfluidic Device Enabling Efficient Bioparticle Conjugation in Biological Assays.

Conjugating a micro/nanoparticle with the biomolecule has proved useful in diagnosing complex diseases (cancer/sepsis). The properties of the conjugating particle help in quantifying, enumerating, and detecting the target species. The conjugation technique has found its applications in diagnostics and therapy, biosensing, and sorting. The major drawback of state-of-the-art conjugation techniques is that they are time-consuming and labor-intensive. One possible solution to the problem posed by the existing conjugation technique is to use microfluidic devices. Microfluidic devices with their precise control, variable geometry, high mixing, and mass transfer efficiencies are widely used in fluid mixing applications. 3Dprinted microfluidic devices have been used to study the conjugation of particles and the detection of different cells in many state-of-the-art studies. In this study, a planer 3D printed micromixer with multiple serpentine channels was developed. The performance of the device was evaluated by performing numerical simulations and running the fluids at various flow rates through the serpentine channels. The numerical simulations produced a fluidic mixing index of ~0.96 at various mesh configurations. Similar particle conjugation efficiency was achieved in just ~3-5 minutes as compared to hours of incubation with state-of-the-art conjugation protocols.