Hydrogel-based microRNA (miRNA) assays typically rely on diffusion-driven transport, resulting in slow target delivery and prolonged analysis times. Here, we presented a forced-convection hydrogel platform in which all injected samples were forced to pass through a permeable polyethylene glycol (PEG)-based hydrogel polymerized within a glass channel. This configuration enables rapid and efficient transport of target miRNAs into the hydrogel matrix, reducing the total assay time to 55 min while achieving high sensitivity, with a limit of detection as low as ∼20 fM. In addition, multiplexed assays were achieved by serially arranging multiple porous hydrogels in a single channel. Together, these results demonstrate that convection-driven mass transport substantially enhances the speed of hydrogel-based assays without compromising sensitivity, suggesting a reliable strategy for rapid, multiplexed miRNA profiling.
Park et al. (Tue,) studied this question.