AIE-based superwettable microchips for evaporation and aggregation induced fluorescence enhancement biosensing.

Superwettable microchips with superhydrophilic microwells on superhydrophobic substrate have attracted increasing attention in fluorescence-based biological and medical diagnostics. However, traditional fluorophores often suffer from the aggregation-caused quenching (ACQ) problem at high concentration or in aggregated state. Here, we developed an AIE-based superwettable microchip by combining the evaporation-induced enrichment of superwettable microchips and the aggregation-induced emission of AIEgens together into one chip. Benefitting from the synergistic effect of the above two mechanisms, the AIE molecules (TPE-Z, a tetraphenylethene salt) were enriched from the diluted solution via evaporation and aggregated within the superhydrophilic microwell and then realized the fluorescence enhancement. Based on the dual enhancement effect of the AIE-based superwettable microchip, microRNA-141 (miR-141) can be detected with excellent reproducibility, sensitivity and specificity. A low detection limit of 1 pM can be achieved with higher signal-to-noise ratio than the traditional fluorescent probes. The proposed AIE-based superwettable microchip will provide a simple fluorescence enhancement biosensing platform for rapid, multiplexed and high-throughput analysis of specific targets in environmental monitoring, food safety, medical diagnosis and related research areas.