Development of 3D printed click-and-fit modular microfluidics for an integrated electrochemical platform

In this article, we presented the development of fully modular microfluidic flow cells for an electrochemical using 3D printing. The proposed devices are potentially applied for electrochemical measurements using a small sample volume on a fully portable, reusable, fabricated, low-cost, PDMS-free, and leakage-free flow cell. This concept offers a simple, controllable sample over the conventional electrochemical platform with a three-electrode system, which requires a considerable volume of samples or a non-controllable droplet-based method for sequential protocols. We demonstrated an easy alignment and lock click-and-fit modular microfluidics, for quick and easy assembly and disassembly of flow cell modules using magnetic force instead of the screw, polymer glue, or resin. Two microfluidic modules were presented using tube- and syringe-flow cells (TFC and SFC) to integrate the screen-printed carbon electrodes in the electrochemical sensor. The proof-of-concept of the integrated sensor–microfluidic platforms was conducted under cyclic voltammetry using a tiny volume of a ferricyanide redox probe at only ~ 50 µL, differential pulse voltammetry, and square wave voltammetry. Implementing the proposed click-and-fit microfluidic modules in electrochemical detection achieves higher current peaks than droplet measurements. These flow cell modules are promising for biosensing applications using a small volume of physiological fluid samples. Our finding found that the DPV results show an enhancement sensitivity of approximately 20% using the TFC and SFC.