Analysis of drug–protein interaction in bio-inspired microwells

Emerging Trends in Integrated Digital Microfluidic Platforms for Next-Generation Immunoassays

Technologies based on digital microfluidics (DMF) have made significant advancements in the automated manipulation of microscale liquids and complex multistep processes. Due to their numerous benefits, such as automation, speed, cost-effectiveness, and minimal sample volume requirements, these systems are particularly well suited for immunoassays. In this review, an overview is provided of diverse DMF manipulation platforms and their applications in immunological analysis. Initially, droplet-driven DMF platforms based on electrowetting on dielectric (EWOD), magnetic manipulation, surface acoustic wave (SAW), and other related technologies are briefly introduced. The preparation of DMF is then described, including material selection, fabrication techniques and droplet generation. Subsequently, a comprehensive account of advancements in the integration of DMF with various immunoassay techniques is offered, encompassing colorimetric, direct chemiluminescence, enzymatic chemiluminescence, electrosensory, and other immunoassays. Ultimately, the potential challenges and future perspectives in this burgeoning field are delved into.

Recent advances in magnetic digital microfluidic platforms

Magnetic Digital microfluidics (DMF), which enables the manipulation of droplets containing different types of samples and reagents by permanent magnets or electromagnet arrays, has been used as a promising platform technology for bioanalytical and preparative assays. This is due to its unique advantages such as simple and "power free" operation, easy assembly, great compatibility with auto control systems, and dual functionality of magnetic particles (actuation and target attachment). Over the past decades, magnetic DMF technique has gained a widespread attention in many fields such as sample-to-answer molecular diagnostics, immunoassays, cell assays, on-demand chemical synthesis, and single-cell manipulation. In the first part of this review, we summarised features of magnetic DMF. Then, we introduced the actuation mechanisms and fabrication of magnetic DMF. Furthermore, we discussed five main applications of magnetic DMF, namely drug screening, protein assays, polymerase chain reaction (PCR), cell manipulation, and chemical analysis and synthesis. In the last part of the review, current challenges and limitations with magnetic DMF technique were discussed, such as biocompatibility, automation of microdroplet control systems, and microdroplet evaporation, with an eye on towards future development.